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Sample records for cubic nacl type

  1. Bonding in scandium monosulfide a NaCl crystal type

    SciTech Connect

    Merrick, J.A.

    1980-08-01

    The transition temperature of an order-disorder transition in Sc/sub 0/ /sub 81/S (R anti 3m to Fm3m) occurs at 700/sup 0/C. A group of ordered sublattices on the NaCl-type lattice (Fm3m) was generated and a Madelung energy and configurational entropy were calculated for each sublattice assuming the ions to be Sc/sup 2/ /sup 48 +/ and S/sup 2 -/. Mean field and pair interaction approximations were used to model long-range and short-range orderings, respectively. The electrostatic model fails to predict the observed short-range and long-range orderings. The high temperature vaporization of ScP was investigated by mass spectrometry and target collection Knudsen effusion at 1767 to 2209K. The composition ScP/sub 1/ /sub 00/ vaporizes congruently to the gaseous species Sc, P, and P/sub 2/. A temperature independent third law enthalpy of atomization (..delta..H/sup 0//sub atom,298/ = 252.2 +- 2.8 kcal mole/sup -1/) has a value approx. 12 kcal larger than that reported for ScS. Nonrelativistic, nonself-consistent LAPW band structure calculations are reported for ScS. XPS and UPS measurements are reported for Sc/sub 2/S/sub 3/ and several compositions Sc/sub 1-x/S (0.0 less than or equal to x less than or equal to 0.2). The Sc and S 2p binding energies (XPS) obtained for the defect scandium monosulfides are very close to those found in the pure elements, suggesting covalent bonding. The Sc 2p energy region has an interesting satellite structure.

  2. Antisolvent crystallization of NaCl using the minute-bubble technique - Effects of different antisolvent types

    NASA Astrophysics Data System (ADS)

    Wada, Yoshinari; Matsumoto, Masakazu; Onoe, Kaoru

    2016-08-01

    To develop a crystallization technique that enables the control of the crystal size distribution, antisolvent crystallization of sodium chloride (NaCl) under a continuous supply of N2 minute-bubbles was performed. The effects of the additive volume ratio of ethanol (EtOH) on the molar yield and size distribution of the NaCl crystals and the effects of the antisolvent type on crystallization phenomena of NaCl were examined. The initial concentration of NaCl in the saturated solution was set at 5.54 mol/l, and EtOH was added as an antisolvent to the saturated NaCl solution, where the added volume ratio of EtOH was in the range of 5 to 50 vol% (as EtOH/NaCl system). As a comparison, the antisolvent crystallization phenomenon of NaCl in a MeOH/NaCl system was also investigated. N2 minute-bubbles with an average bubble size of 40 μm were continuously supplied to the NaCl supersaturated solution using a self-supporting bubble generator, and NaCl was crystallized. Consequently, the production enhancement and crystal size minimization of NaCl were caused by the residence of minute-bubbles because of the acceleration of nucleation and the inhibition of crystal coalescence. Moreover, the results indicated that the enhancement effect of NaCl crystal production and the minimizing effect of average crystal size depended on the additive volume and the type of alcohol as antisolvent.

  3. Anodic etching of p-type cubic silicon carbide

    NASA Technical Reports Server (NTRS)

    Harris, G. L.; Fekade, K.; Wongchotigul, K.

    1992-01-01

    p-Type cubic silicon carbide was anodically etched using an electrolyte of HF:HCl:H2O. The etching depth was determined versus time with a fixed current density of 96.4 mA/sq cm. It was found that the etching was very smooth and very uniform. An etch rate of 22.7 nm/s was obtained in a 1:1:50 HF:HCl:H2O electrolyte.

  4. Low pH-Induced Pore Formation by the T Domain of Botulinum Toxin Type A is Dependent upon NaCl Concentration

    SciTech Connect

    Lai, B.; Swaminathan, S.; Agarwal, R.; Nelson, L. D.; London, E.

    2010-07-19

    Botulinum neurotoxins (BoNTs) undergo low pH-triggered membrane insertion, resulting in the translocation of their light (catalytic) chains into the cytoplasm. The T (translocation) domain of the BoNT heavy chain is believed to carry out translocation. Here, the behavior of isolated T domain from BoNT type A has been characterized, both in solution and when associated with model membranes. When BoNT T domain prepared in the detergent dodecylmaltoside was diluted into aqueous solution, it exhibited a low pH-dependent conformational change below pH 6. At low pH the T domain associated with, and formed pores within, model membrane vesicles composed of 30 mol% dioleoylphosphatidylglycerol/70 mol% dioleoylphosphatidylcholine. Although T domain interacted with vesicles at low (50 mM) and high (400 mM) NaCl concentrations, the interaction required much less lipid at low salt. However, even at high lipid concentrations pore formation was much more pronounced at low NaCl concentrations than at high NaCl concentration. Increasing salt concentration after insertion in the presence of 50 mM NaCl did not decrease pore formation. A similar effect of NaCl concentration upon pore formation was observed in vesicles composed solely of dioleoylphosphatidylcholine, showing that the effect of NaCl did not solely involve modulation of electrostatic interactions between protein and anionic lipids. These results indicate that some feature of membrane-bound T domain tertiary structure critical for pore formation is highly dependent upon salt concentration.

  5. Traveling waves for conservation laws with cubic nonlinearity and BBM type dispersion

    NASA Astrophysics Data System (ADS)

    Shearer, Michael; Spayd, Kimberly R.; Swanson, Ellen R.

    2015-10-01

    Scalar conservation laws with non-convex fluxes have shock wave solutions that violate the Lax entropy condition. In this paper, such solutions are selected by showing that some of them have corresponding traveling waves for the equation supplemented with dissipative and dispersive higher-order terms. For a cubic flux, traveling waves can be calculated explicitly for linear dissipative and dispersive terms. Information about their existence can be used to solve the Riemann problem, in which we find solutions for some data that are different from the classical Lax-Oleinik construction. We consider dispersive terms of a BBM type and show that the calculation of traveling waves is somewhat more intricate than for a KdV-type dispersion. The explicit calculation is based upon the calculation of parabolic invariant manifolds for the associated ODE describing traveling waves. The results extend to the p-system of one-dimensional elasticity with a cubic stress-strain law.

  6. The Effect of Surface Roughness on the Corrosion Properties of Type AISI 304 Stainless Steel in Diluted NaCl and Urban Rain Solution

    NASA Astrophysics Data System (ADS)

    Leban, Mirjam Bajt; Mikyška, Črt; Kosec, Tadeja; Markoli, Boštjan; Kovač, Janez

    2014-05-01

    Due to their good corrosion resistance, favorable mechanical properties, and reasonable price regarding their excellent properties, austenitic stainless steels have, over recent decades, become one of the alloys that are increasingly used in civil engineering and building, as well as for specific architectural purposes. Architects often design stainless steel exterior elements with higher surface roughnesses, which are not resistant to corrosion processes. The aim of this work was to investigate the influence of different types of surface finishes to stainless steel of quality AISI 304 on the corrosion properties of this steel. In order to achieve this goal, electrochemical tests were performed on different surface finishes in two different environments: in an NaCl aqueous solution, and in simulated urban rain which contained no chlorides. In addition to the electrochemical methods used, surface roughness was also measured, and XPS surface analyses were performed. The results of the investigation showed that surface roughness affects the growth of the passive layer in urban rain significantly; however, the growth of such a film is retarded in the case of the NaCl aqueous solution. Based on the results of the performed analyses, it was found that, in the NaCl solution, the pitting potential depended strongly upon the surface roughness and the surface finish, but this was not true for the samples tested in urban rain.

  7. The effect of NaCl on stomatal opening in Arabidopsis wild type and agb1 heterotrimeric G-protein mutant plants

    PubMed Central

    Yu, Yunqing; Assmann, Sarah M.

    2016-01-01

    Salinity is a major agricultural problem that affects crop yield. Na+ is transported to the shoot through the transpiration stream. The mutant of the sole Arabidopsis heterotrimeric G protein β subunit, agb1, is hypersensitive to salinity in part due to a higher transpiration rate. Here, we investigated the direct effect of Na+ on stomatal opening using detached epidermal peels of wild type and agb1 plants. In both genotypes, NaCl is equally as effective as KCl in mediating stomatal opening at the concentrations tested. In both genotypes, ABA is less effective in inhibiting Na+ mediated stomatal opening than K+ mediated stomatal opening. The agb1 mutant is hyposensitive to ABA inhibition of K+-mediated but not Na+-mediated stomatal opening. These results suggest that the greater transpiration observed in agb1 plants grown in saline conditions is likely not mediated by differential genotypic direct effects of Na+ on stomatal apertures. PMID:26431457

  8. The effect of NaCl on stomatal opening in Arabidopsis wild type and agb1 heterotrimeric G-protein mutant plants.

    PubMed

    Yu, Yunqing; Assmann, Sarah M

    2016-01-01

    Salinity is a major agricultural problem that affects crop yield. Na(+) is transported to the shoot through the transpiration stream. The mutant of the sole Arabidopsis heterotrimeric G protein β subunit, agb1, is hypersensitive to salinity in part due to a higher transpiration rate. Here, we investigated the direct effect of Na(+) on stomatal opening using detached epidermal peels of wild type and agb1 plants. In both genotypes, NaCl is equally as effective as KCl in mediating stomatal opening at the concentrations tested. In both genotypes, ABA is less effective in inhibiting Na(+) mediated stomatal opening than K(+) mediated stomatal opening. The agb1 mutant is hyposensitive to ABA inhibition of K(+)-mediated but not Na(+)-mediated stomatal opening. These results suggest that the greater transpiration observed in agb1 plants grown in saline conditions is likely not mediated by differential genotypic direct effects of Na(+) on stomatal apertures. PMID:26431457

  9. Small-angle neutron and X-ray scattering from amphiphilic stimuli-responsive diamond-type bicontinuous cubic phase.

    PubMed

    Angelov, Borislav; Angelova, Angelina; Garamus, Vasil M; Lebas, Geneviève; Lesieur, Sylviane; Ollivon, Michel; Funari, Sérgio S; Willumeit, Regine; Couvreur, Patrick

    2007-11-01

    The structural evolution of a diamond-type bicontinuous lipid cubic phase upon application of thermal and chemical (hydration agent) stimuli is investigated by means of small-angle neutron (SANS) and X-ray scattering (SAXS). The soft-matter cubic architecture responds by dramatic swelling (DLarge cubic structure) upon incorporation of a hydration-enhancing guest component (octyl glucoside) at low and ambient temperatures, the aqueous channel diameter increasing twice to approximately 7 nm. DLarge appears to be built up from an assembly of cubosomic domains, which may coexist with an amphiphilic lamellae domain at low temperatures. The chemical stimulus concentration can be selected as to tune the hydration of the nanochannels in the DLarge phase and its transformation into a DNormal phase at temperatures above the body temperature. Two-dimensional SANS images recorded upon heating scan reveal growth of spontaneously oriented domains of single-crystal cubic nature. Phase separation and squeezing out the guest-hydrating agent from the higher-curvature regions of the amphiphilic bilayer suggest a possible mechanism for the established transformations. The order-order structural transition, cubic DLarge-cubic DNormal, is found to be reversible upon cooling. The obtained results put forward a structure-based concept for release of encapsulated guest molecules from stimuli-responsive and self-regulated cubosomic nanocarriers. PMID:17929809

  10. Effects of fibre type and structure of longissimus lumborum (Ll), biceps femoris (Bf) and semimembranosus (Sm) deer muscles salting with different Nacl addition on proteolysis index and texture of dry-cured meats.

    PubMed

    Żochowska-Kujawska, J

    2016-11-01

    The aim of the present study was to describe the effect of fibre type and structure as well as NaCl level on the proteolysis index and texture parameters observed in dry-cured meats produced from individual deer muscles. The biceps femoris, semimembranosus and longissimus lumborum muscles were cut from deer main elements, shaped into blocks by trimming off the edges, cured by adding 4, 6 and 8% of salt (w/w) and dried in a ripening chamber for 29days. The results indicated that deer dry-cured muscles with higher percentage of red fibres (type I) showed higher texture parameters, proteolysis index as well as lower moisture losses than muscles with higher amount of white fibres (type IIB). Dry-cured deer muscles with lower NaCl content showed higher values of proteolysis index and lower hardness, cohesiveness, springiness, and chewiness, as well as lower changes in structure elements. PMID:27442183

  11. On Schrödinger systems with cubic dissipative nonlinearities of derivative type

    NASA Astrophysics Data System (ADS)

    Li, Chunhua; Sunagawa, Hideaki

    2016-05-01

    Consider the initial value problem for systems of cubic derivative nonlinear Schrödinger equations in one space dimension with the masses satisfying a suitable resonance relation. We give structural conditions on the nonlinearity under which the small data solution gains an additional logarithmic decay as t\\to +∞ compared with the corresponding free evolution.

  12. Effect of the introduction of oxide ion vacancies into cubic fluorite-type rare earth oxides on the NO decomposition catalysis

    SciTech Connect

    Masui, Toshiyuki; Nagai, Ryosuke; Imanaka, Nobuhito

    2014-12-15

    Cubic fluorite-type solid solutions based on Pr{sub 6}O{sub 11} and CeO{sub 2} were synthesized and oxide anion vacancies were intentionally introduced into the cubic fluorite-type lattice through the charge compensating mechanism by Mg{sup 2+} and/or Ca{sup 2+} doping into their lattices. The oxide anion vacancies bring about positive effect on NO decomposition catalysis. The reason for the increase in the catalytic activity was attributed to defect fluorite-type structures close to the C-type cubic one, because C-type cubic rare earth oxides, in which one-quarter of the oxygen atoms in the fluorite-type structure are removed, show high NO decomposition activity. In particular, the positive effect of the formation of oxide anion vacancies was significant for Pr{sub 6}O{sub 11} and its solid solutions, because the molar volume of Pr{sub 6}O{sub 11} is larger than that of CeO{sub 2}, and Pr{sub 6}O{sub 11} contains Pr{sup 3+} as well as Pr{sup 4+} and thereby a small amount of oxide anion vacancies exist inherently in the lattice. - Graphical abstract: Oxide anion vacancies intentionally introduced into the cubic fluorite-type lattice bring about positive effect on NO decomposition catalysis. - Highlights: • Cubic fluorite-type solid solutions were synthesized. • Oxide anion vacancies were intentionally introduced into the cubic fluorite-type lattice. • The oxide anion vacancies bring about positive effect on NO decomposition catalysis. • The activity was enhanced by making the structure close to the C-type cubic one.

  13. Infrared thermography monitoring of the NaCl crystallisation process

    NASA Astrophysics Data System (ADS)

    Vázquez, Patricia; Thomachot-Schneider, Céline; Mouhoubi, Kamel; Fronteau, Gilles; Gommeaux, Maxime; Benavente, David; Barbin, Vincent; Bodnar, Jean-Luc

    2015-07-01

    In this work, we describe the growth of NaCl crystals by evaporating droplets of aqueous solution while monitoring them with infrared thermography. Over the course of the evaporation experiments, variations in the recorded signal were observed and interpreted as being the result of evaporation and crystallisation. In particular, we observed sharp and transient decreases in the thermosignal during the later stages of high-concentration drop evaporation. The number of such events per experiment, referred to as "pop-cold events", varied from 1 to over 100 and had durations from 1 to 15 s. These events are interpreted as a consequence from the top-supplied creeping (TSC) of the solution feeding the growth of efflorescence-like crystals. This phenomenon occurred when the solution was no longer macroscopically visible. In this case, efflorescence-like crystals with a spherulite shape grew around previously formed cubic crystals. Other crystal morphologies were also observed but were likely fed by mass diffusion or bottom-supplied creeping (BSC) and were not associated with "pop-cold events"; these morphologies included the cubic crystals at the centre, ring-shaped at the edge of droplets and fan-shaped crystals. After complete evaporation, an analysis of the numbers and sizes of the different types of crystals was performed using image processing. Clear differences in their sizes and distribution were observed in relation to the salt concentration. Infrared thermography permitted a level of quantification that previously was only possible using other techniques. As example, the intermittent efflorescence growth process was clearly observed and measured for the first time using infrared thermography.

  14. Thermal stability and thermal expansion studies of cubic fluorite-type MgF{sub 2} up to 135 GPa

    SciTech Connect

    Sun, X.W.; Song, T.; Wei, X.P.; Quan, W.L.; Liu, X.B.; Su, W.F.

    2014-04-01

    Highlights: • The thermal expansion of MgF{sub 2} with a fluorite-type structure has been investigated. • The quasi-harmonic Debye model is applied to take into account the thermal effect. • Particular attention is paid to the prediction of thermal expansion for the first time. - Abstract: The thermal expansion of MgF{sub 2} with a fluorite structure has been investigated at high pressures using plane-wave pseudopotential scheme within the local density approximation correction in the frame of density functional theory based on the analysis of thermal stability using classical molecular dynamics simulations up to 6500 K. To investigate the thermodynamic properties like as the P–V–T equation of state and volumetric thermal expansion coefficient α{sub V} of cubic fluorite-type MgF{sub 2} at extended pressure and temperature ranges, we apply the quasi-harmonic Debye model in which the phononic effects are considered. The P–V relationship and α{sub V} dependence of the pressure up to 135 GPa at different temperatures, and the V–T relationship and α{sub V} dependence of the temperature up to the melting temperature 1500 K at different pressures have been obtained.

  15. Melting curve of NaCl determined using synchrotron x-ray radiography

    NASA Astrophysics Data System (ADS)

    Chen, J.; Yu, T.; Long, H.; Wang, L.; Garai, J.

    2009-12-01

    NaCl has been widely used as a pressure calibrant in in-situ high pressure synchrotron x-ray study. The applicable pressure and temperature range of this calibrant is from ambient condition up to B1-B2 transition in pressure and to melting in temperature. Melting data of NaCl at high pressures are still very limited. We have conducted comparative experiments to study melting of NaCl using energy dispersive x-ray diffraction and radiographic imaging at high pressure up to 8.8GPa. The experiments were carried out using the cubic-type multi-anvil pressure (SAM85) at the X17B2 beamline of the National Synchrotron Light Source (NSLS). In the x-ray diffraction experiments, melting is inferred when disappearance of diffraction peak of NaCl from a mixture of NaCl+BN (to reduce possible grain growth) is observed. In the x-ray radiography experiment, a WC sphere is place in the top portion of pure NaCl sample; melting is inferred when the WC sphere start to drop in the sample. The experimental result indicates that the melting temperatures determined from the two types of observations may differ by 60°C at 5 GPa. Due to unavoidable grain growth near melting, x-ray diffraction signals may disappear from the point solid state detector even though the melting is not achieved. Therefore the radiography method may reflect more accurate measurement of melting temperature. Melting curve of NaCl was measured up to 1.8 GPa by Clark et al (1), and between 2 and 4 GPa by Pistorius (2). The new melting data are consistent with the previous results. All the experimental are in good agreement with theoretical prediction using Simon fusion equation (2) and the relation between melting temperature and Debye temperature (3). References: (1) Clark, Jr. Effect of Pressure on the Melting Points of Eight Alkali Halides, Journal of Chemical Physics 31 (6) 1526-1531 (1959). (2) Kraut and Kennedy, New Melting Law at High Pressures, Physical Review 151 (2) 668-675 (1966) (3) J. Garai, and J. Chen

  16. Propagation of time-truncated Airy-type pulses in media with quadratic and cubic dispersion.

    PubMed

    Borda-Hernández, José A; Zamboni-Rached, Michel; Shaarawi, Amr; Besieris, Ioannis M

    2015-10-01

    In this paper, we describe analytically the propagation of Airy-type pulses truncated by a finite-time aperture when second- and third-order dispersion effects are considered. The mathematical method presented here, which is based on the superposition of exponentially truncated Airy pulses, is very effective and allows us to avoid the use of time-consuming numerical simulations. We analyze the behavior of the time-truncated ideal Airy pulse and also the interesting case of a time-truncated Airy pulse with a "defect" in its initial profile, which reveals the self-healing property of this kind of pulse solution. PMID:26479932

  17. Documentation for computer code NACL

    SciTech Connect

    Weres, O.; Peiper, J.C.; Pitzer, K.S.; Pabalan, R.

    1987-02-01

    The computer program NACL incorporates the empirical model of the thermodynamic properties of the system NaCl-H/sub 2/O recently published by Pitzer et al. NACL is derived from the research codes used by Pitzer et al. to analyze the experimental data and fix the parameters in their model. NACL calculates values for all thermodynamic properties which are identical to values tabulated in Ref. 1. NACL is written in VAX/VMS FORTRAN, and was developed on a VAX 8600 computer. Machine specific features have been avoided, and NACL should require few changes to compile and run with other compilers and computers. A sample output and full code listing of NACL are appended to this document. For one year following the publication of this document, the code will be made available to interested users on 5.25'' floppy diskette in MS-DOS 2.11 format. Please send a formatted diskette and a stamped, self-addressed mailer to Oleh Weres, Lawrence Berkeley Laboratory, 50E, Berkeley, CA 94720. Please put your name and address on the diskette.

  18. Abnormal thermal expansion properties of cubic NaZn13-type La(Fe,Al)13 compounds.

    PubMed

    Li, Wen; Huang, Rongjin; Wang, Wei; Zhao, Yuqiang; Li, Shaopeng; Huang, Chuanjun; Li, Laifeng

    2015-02-28

    The cubic NaZn13-type La(Fe,Al)13 compounds were synthesized, and their linear thermal expansion properties were investigated in the temperature range of 4.2-300 K. It was found that these compounds exhibit abnormal thermal expansion behavior, i.e., pronounced negative thermal expansion (NTE) or zero thermal expansion (ZTE) behavior, below the Curie temperature due to the magnetovolume effect (MVE). Moreover, in the La(Fe,Al)13 compounds, the modification of the coefficient of thermal expansion (CTE) as well as the abnormal thermal expansion (ATE) temperature-window is achieved through optimizing the proportion of Fe and Al. Typically, the average CTE of the LaFe13-xAlx compounds with x = 1.8 reaches as large as -10.47 × 10(-6) K(-1) between 100 and 225 K (ΔT = 125 K). Also, the ZTE temperature-window of the LaFe13-xAlx compounds with x = 2.5 and x = 2.7 could be broadened to 245 K (from 5 to 250 K). Besides, the magnetic properties of these compounds were measured and correlated with the abnormal thermal expansion behavior. The present results highlight the potential application of such La(Fe,Al)13 compounds with abnormal thermal expansion properties in cryogenic engineering. PMID:25642468

  19. Higher Dimensional Gaussian-Type Solitons of Nonlinear Schrödinger Equation with Cubic and Power-Law Nonlinearities in PT-Symmetric Potentials

    PubMed Central

    Chen, Yi-Xiang; Xu, Fang-Qian

    2014-01-01

    Two families of Gaussian-type soliton solutions of the (n+1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in -symmetric potentials are analytically derived. As an example, we discuss some dynamical behaviors of two dimensional soliton solutions. Their phase switches, powers and transverse power-flow densities are discussed. Results imply that the powers flow and exchange from the gain toward the loss regions in the cell. Moreover, the linear stability analysis and the direct numerical simulation are carried out, which indicates that spatial Gaussian-type soliton solutions are stable below some thresholds for the imaginary part of -symmetric potentials in the defocusing cubic and focusing power-law nonlinear medium, while they are always unstable for all parameters in other media. PMID:25542020

  20. Stabilization of cubic lithium-stuffed garnets of the type “Li7La3Zr2O12” by addition of gallium

    NASA Astrophysics Data System (ADS)

    El Shinawi, Hany; Janek, Jürgen

    2013-03-01

    Cubic lithium-stuffed garnets of the type Li7La3Zr2O12 have been successfully stabilized by incorporation of gallium. The materials have been prepared by a sol-gel procedure with final calcination at 1085 °C for 6 h. Under the applied synthesis conditions, 0.3 mole of gallium ions (per mole of Li7La3Zr2O12) were sufficient to fully stabilize the cubic garnet-type phase. Increasing the fraction of gallium led to significant improvement of sinterability and lithium ion conductivity. Excess gallium ions, in the form of LiGaO2, act as a sintering aid and reside exclusively at the grain boundaries. The gallium-modified garnets showed conductivities up to 5.4 × 10-4 S cm-1 at 20 °C, and activation energies in the range 0.32-0.37 eV.

  1. Hybrid thermoelastic properties of NaCl

    NASA Astrophysics Data System (ADS)

    Wentzcovitch, R. M.; Marcondes, M. L.; Shukla, G.

    2015-12-01

    Despite the importance of thermoelastic properties of minerals in geophysics, their measurements at high pressures and temperatures are limited. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy and to approximations used in calculations of vibrational effects, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a hybrid scheme to reconcile calculated and measured elastic coefficients and apply it to rock-salt-type NaCl, a challenging material to describe by ab initio and an important mineral in the context of oil/gas exploration. The approach is predictive within the temperature range of validity of the quasiharmonic approximation and results are used to generate velocities of NaCl at desirable geological conditions. [1] Marcondes, M. L. & Wentzcovitch, R.M. (2015). Hybrid ab-initio/experimental thermal equations of state: application to the NaCl pressure scale, J. Appl. Phys. 117:215902.

  2. Electron scattering in graphene with adsorbed NaCl nanoparticles

    SciTech Connect

    Drabińska, Aneta Kaźmierczak, Piotr; Bożek, Rafał; Karpierz, Ewelina; Wysmołek, Andrzej; Kamińska, Maria; Wołoś, Agnieszka; Krajewska, Aleksandra

    2015-01-07

    In this work, the results of contactless magnetoconductance and Raman spectroscopy measurements performed for a graphene sample after its immersion in NaCl solution were presented. The properties of the immersed sample were compared with those of a non-immersed reference sample. Atomic force microscopy and electron spin resonance experiments confirmed the deposition of NaCl nanoparticles on the graphene surface. A weak localization signal observed using contactless magnetoconductance showed the reduction of the coherence length after NaCl treatment of graphene. Temperature dependence of the coherence length indicated a change from ballistic to diffusive regime in electron transport after NaCl treatment. The main inelastic scattering process was of the electron-electron type but the major reason for the reduction of the coherence length at low temperatures was additional, temperature independent, inelastic scattering. We associate it with spin flip scattering, caused by NaCl nanoparticles present on the graphene surface. Raman spectroscopy showed an increase in the D and D′ bands intensities for graphene after its immersion in NaCl solution. An analysis of the D, D′, and G bands intensities proved that this additional scattering is related to the decoration of vacancies and grain boundaries with NaCl nanoparticles, as well as generation of new on-site defects as a result of the decoration of the graphene surface with NaCl nanoparticles. The observed energy shifts of 2D and G bands indicated that NaCl deposition on the graphene surface did not change carrier concentration, but reduced compressive biaxial strain in the graphene layer.

  3. Effect of competing cubic-quintic nonlinearities on the modulational instability in nonlocal Kerr-type media

    NASA Astrophysics Data System (ADS)

    Tagwo, H.; Tiofack, C. G. L.; Dafounansou, O.; Mohamadou, A.; Kofane, T. C.

    2016-03-01

    We investigate analytically and numerically the modulational instability (MI) of plane waves under competing nonlocal cubic-local quintic nonlinearities. The generic properties of the MI gain spectra are then demonstrated for the Gaussian response function, exponential response function, and rectangular response function. Special attention is paid to competing nonlocal cubic-local quintic nonlinearities on the MI. We observe that the focusing local quintic nonlinearity increases the growth rate and bandwidth of instability contrary to the small values of defocusing local quintic nonlinearity which decrease the growth rate and bandwidth of instability. Numerical simulations of the full model equation describing the dynamics of the waves are been carried out and leads to the development of pulse trains, depending upon the sign the quintic nonlinearity.

  4. Cubic Icosahedra? A Problem in Assigning Symmetry

    ERIC Educational Resources Information Center

    Lloyd, D. R.

    2010-01-01

    There is a standard convention that the icosahedral groups are classified separately from the cubic groups, but these two symmetry types have been conflated as "cubic" in some chemistry textbooks. In this note, the connection between cubic and icosahedral symmetries is examined, using a simple pictorial model. It is shown that octahedral and…

  5. Genetic Architecture of NaCl Tolerance in Arabidopsis1

    PubMed Central

    Quesada, Víctor; García-Martínez, Santiago; Piqueras, Pedro; Ponce, María Rosa; Micol, José Luis

    2002-01-01

    The little success of breeding approaches toward the improvement of salt tolerance in crop species is thought to be attributable to the quantitative nature of most, if not all the processes implicated. Hence, the identification of some of the quantitative trait loci (QTL) that contribute to natural variation in salt tolerance should be instrumental in eventually manipulating the perception of salinity and the corresponding responses. A good choice to reach this goal is the plant model system Arabidopsis, whose complete genome sequence is now available. Aiming to analyze natural variability in salt tolerance, we have compared the ability of 102 wild-type races (named ecotypes or accessions) of Arabidopsis to germinate on 250 mm NaCl, finding a wide range of variation among them. Accessions displaying extremely different responses to NaCl were intercrossed, and the phenotypes found in their F2 progenies suggested that natural variation in NaCl tolerance during germination was under polygenic controls. Genetic distances calculated on the basis of variations in repeat number at 22 microsatellites, were analyzed in a group of either extremely salt-tolerant or extremely salt-sensitive accessions. We found that most but not all accessions with similar responses to NaCl are phylogenetically related. NaCl tolerance was also studied in 100 recombinant inbred lines derived from a cross between the Columbia-4 and Landsberg erecta accessions. We detected 11 QTL harboring naturally occurring alleles that contribute to natural variation in NaCl tolerance in Arabidopsis, six at the germination and five at the vegetative growth stages, respectively. At least five of these QTL are likely to represent loci not yet described by their relationship with salt stress. PMID:12376659

  6. Molecular dynamics simulation of NaCl dissolution.

    PubMed

    Lanaro, Gabriele; Patey, G N

    2015-03-19

    Molecular dynamics simulations are used to investigate the dissolution of NaCl nanocrystals (containing ∼2400 ions) in water. We focus on systems under sink conditions at 300 K, but the influences of concentration and temperature are also investigated. Cubical, spherical, tablet-shaped, and rod-shaped nanocrystals are considered, and it is shown that the initial shape can influence the dissolution process. Dissolution is observed to occur in three stages: an initial period where the most exposed ions are removed from the crystal surface, and the crystal takes on a solution-annealed shape which persists throughout the second stage of dissolution; a second long intermediate stage where dissolution roughly follows a fixed rate law; and a final stage where the small residual crystal (≲200 ions) dissolves at an ever increasing rate until it disappears. The second stage of dissolution which applies for most of the dissolution process is well described by classical rate equations which simply assume that the dissolution rate is proportional to an active surface area from which ions are most easily detached from the crystal. The active area depends on the initial crystal shape. We show that for our model NaCl nanocrystals the rate-determining step for dissolution under sink conditions is ion detachment from the crystal, and that diffusion layers do not exist for these systems. PMID:25704286

  7. Mixed-type vector solitons for the coupled cubic-quintic nonlinear Schrödinger equations with variable coefficients in an optical fiber

    NASA Astrophysics Data System (ADS)

    Chai, Jun; Tian, Bo; Wang, Yu-Feng; Zhen, Hui-Ling; Wang, Yun-Po

    2015-09-01

    In this paper, we investigate the coupled cubic-quintic nonlinear Schrödinger equations with variable coefficients, which describe the effects of quintic nonlinearity for the ultrashort optical pulse propagation in a non-Kerr medium, or in the twin-core nonlinear optical fiber or waveguide. Under certain constraints on the variable coefficients in such equations, mixed-type (bright-dark) vector one- and two-soliton solutions are derived via the Hirota method and symbolic computation, and such vector-soliton solutions are only related to the delayed nonlinear response effect and nonlinearity. Through the graphic analysis, we find that the delayed nonlinear response effect and nonlinearity can both affect the vector-soliton amplitude, while the vector-soliton velocity merely depends on the delayed nonlinear response effect. With the choice on the variable coefficients representing the delayed nonlinear response effect and nonlinearity, interactions between the amplitude- and velocity-unchanging, amplitude-changing, velocity-changing and amplitude- and velocity-changing vector two solitons are obtained. We see that the interaction between the vector two solitons is elastic. We also find that the interaction period of the bound vector solitons decreases as the increase of the delayed nonlinear response effect or increases as the decrease of the delayed nonlinear response effect, but is independent of the nonlinearity.

  8. Design and synthesis of new type I bicontinuous cubic lyotropic liquid crystal monomers based on the gemini framework for molecular-size separation applications

    NASA Astrophysics Data System (ADS)

    Wiesenauer, Brian R.

    The overall objective of this thesis research was the design and synthesis of new type I bicontinuous cubic (QI) phase-forming, gemini-shaped lyotropic liquid crystal (LLC) monomers for the preparation of nanoporous polymer membrane materials. These new QI-phase LLC monomers were designed to overcome several shortcomings of previously developed QI-phase LLC monomers in the Gin research group that include expensive and difficult synthesis, poor film processibility, and limited blendability with additives. The first method for obtaining this objective was the synthesis of six homologues of a new gemini ammonium LLC monomer, two of which exhibit a QI phase with water. Both of these LLCs form a robust Q I phase such that a gel of these materials can be fully infused into a microporous support membrane and then cross-linked to maintain the LLC phase structure. The resulting QI-phase polymer film showed a uniform pore size of 0.86 nm in water nanofiltration and desalination experiments. This QI monomer platform is less costly and less rigorous to synthesize than previously synthesized phosphonium-based gemini QI LLC monomers. These new LLC monomers also have the ability to blend with the hydrophobic, commercially available cross-linkable elastomer vinyl-EPDM (v-EPDM) to form breathable composite barrier materials. In the appropriate composition, melt-infused gemini ammonium monomer/v-EPDM polymer membranes exhibit extremely high pure water vapor fluxes, and high rejection of toxic industrial chemical vapors. A new cross-linkable gemini LLC monomer based on charged imidazolium units was also developed that forms a QI phase with glycerol. This new LLC monomer can be solution-cast from MeOH and UV-irradiated to form cross-linked thin-film composite QI membranes with slightly larger effective pore size (0.96 nm) than the previous systems. A related goal of this thesis research was to develop methods for systematically tuning the effective pore size of nanoporous QI polymer

  9. A Multifunctional Sensor for Concentrations of Ternary Solution with NaCl and Sucrose Employed in Osmotic Dehydration Process

    NASA Astrophysics Data System (ADS)

    Wei, Guo; Shida, Katsunori

    2003-08-01

    Ternary solution with NaCl and sucrose is widely employed in the osmotic dehydration process of food. In this paper we present a multifunctional sensor capable of directly sensing temperature and two physical parameters of solutions, namely ultrasonic velocity and electrical conductivity. By combination measurement of these three measurable parameters, the concentrations of various components in ternary solution with NaCl and sucrose can be simultaneously determined. A regression algorithm based on natural cubic spline interpolation and the least squares method is developed to estimate the concentrations of NaCl and sucrose, which considers the temperature influence on the multifunctional sensor and then enables decoupling of the reconstruction of concentrations in 4D space into 3D space. This sensor could prove valuable as a process control sensor in food industry.

  10. Piecewise Cubic Interpolation Package

    Energy Science and Technology Software Center (ESTSC)

    1982-04-23

    PCHIP (Piecewise Cubic Interpolation Package) is a set of subroutines for piecewise cubic Hermite interpolation of data. It features software to produce a monotone and "visually pleasing" interpolant to monotone data. Such an interpolant may be more reasonable than a cubic spline if the data contain both 'steep' and 'flat' sections. Interpolation of cumulative probability distribution functions is another application. In PCHIP, all piecewise cubic functions are represented in cubic Hermite form; that is, f(x)more » is determined by its values f(i) and derivatives d(i) at the breakpoints x(i), i=1(1)N. PCHIP contains three routines - PCHIM, PCHIC, and PCHSP to determine derivative values, six routines - CHFEV, PCHFE, CHFDV, PCHFD, PCHID, and PCHIA to evaluate, differentiate, or integrate the resulting cubic Hermite function, and one routine to check for monotonicity. A FORTRAN 77 version and SLATEC version of PCHIP are included.« less

  11. Structure and properties of rhombohedral CePd{sub 3}Ga{sub 8}: A variant of the cubic parent compound with BaHg{sub 11} structure type

    SciTech Connect

    Macaluso, Robin T.; Francisco, Melanie; Young, David P.; Stadler, Shane; Mitchell, John F.; Geiser, Urs; Hong, Han-yul; Kanatzidis, Mercouri G.

    2011-12-15

    Single crystals of a new intermetallic gallide, R-CePd{sub 3}Ga{sub 8}, have been synthesized from excess molten gallium. Single-crystal X-ray diffraction reveals that R-CePd{sub 3}Ga{sub 8} crystallizes in the R-3m space group with a=b=c=8.4903(10) A and {alpha}={beta}={gamma}=89.993(17). R-CePd{sub 3}Ga{sub 8} is a variant of the cubic BaHg{sub 11} structure type with three structural units: a Ce-centered polyhedron, a distorted cube of Pd{sub 2}Ga{sub 6} and a Pd-centered cuboctahedron. The distortions of these units are compared to undistorted analogous units in intermetallic compounds with BaHg{sub 11} structure type. Field and temperature-dependent magnetization measurements on R-CePd{sub 3}Ga{sub 8} reveal a paramagnetic material with strong antiferromagnetic correlations and a magnetization consistent with Ce{sup 3+}. Electrical resistance measurements indicate Kondo behavior between localized Ce{sup 3+} magnetic moments. - Graphical Abstract: Single crystals of CePd{sub 3}Ga{sub 8} have been synthesized from Ga flux. This new compound is the first rhombohedral variant of the cubic BaHg{sub 11} structure type. Highlights: Black-Right-Pointing-Triangle Single crystals of CePd{sub 3}Ga{sub 8} were synthesized from gallium flux. Black-Right-Pointing-Triangle CePd{sub 3}Ga{sub 8} is the first rhombohedral variant of the cubic BaHg{sub 11} structure type. Black-Right-Pointing-Triangle Paramagnetic with antiferromagnetic correlations. Black-Right-Pointing-Triangle Magnetization consistent with Ce{sup 3+}.

  12. High-temperature single-crystal X-ray diffraction study of tetragonal and cubic perovskite-type PbTiO3 phases.

    PubMed

    Yoshiasa, Akira; Nakatani, Tomotaka; Nakatsuka, Akihiko; Okube, Maki; Sugiyama, Kazumasa; Mashimo, Tsutomu

    2016-06-01

    A high-temperature single-crystal X-ray diffraction study of a synthetic PbTiO3 perovskite was carried out over the wide temperature range 298-928 K. A transition from a tetragonal (P4mm) to a cubic (Pm \\bar 3 m) phase has been revealed near 753 K. In the non-centrosymmetric P4mm symmetry group, the difference in relative displacement between Pb and O along the c-axis is much larger than that between Ti and O. The Pb and Ti cations contribute sufficiently to polarization being shifted in the opposite direction compared with the shift of O atoms. Deviation from the linear changes in Debye-Waller factors and bonding distances in the tetragonal phases can be interpreted as a precursor phenomenon before the phase transition. Disturbance of the temperature factor Ueq for O is observed in the vicinity of the transition point, while Ueq values for Pb and Ti are continuously changing with increasing temperature. The O site includes the clear configurational disorder in the cubic phase. The polar local positional distortions remain in the cubic phase and are regarded as the cause of the paraelectricity. Estimated values of the Debye temperature ΘD for Pb and Ti are 154 and 467 K in the tetragonal phase and decrease 22% in the high-temperature phase. Effective potentials for Pb and Ti change significantly and become soft after the phase transition. PMID:27240769

  13. Variable-temperature single-crystal X-ray diffraction study of tetragonal and cubic perovskite-type barium titanate phases.

    PubMed

    Nakatani, Tomotaka; Yoshiasa, Akira; Nakatsuka, Akihiko; Hiratoko, Tatsuya; Mashimo, Tsutomu; Okube, Maki; Sasaki, Satoshi

    2016-02-01

    A variable-temperature single-crystal X-ray diffraction study of a synthetic BaTiO3 perovskite has been performed over the temperature range 298-778 K. A transition from a tetragonal (P4mm) to a cubic (Pm \\overline 3 m) phase has been revealed near 413 K. In the non-centrosymmetric P4mm symmetry group, both Ti and O atoms are displaced along the c-axis in opposite directions with regard to the Ba position fixed at the origin, so that Ti(4+) and Ba(2+) cations occupy off-center positions in the TiO6 and BaO12 polyhedra, respectively. Smooth temperature-dependent changes of the atomic coordinates become discontinuous with the phase transition. Our observations imply that the cations remain off-center even in the high-temperature cubic phase. The temperature dependence of the mean-square displacements of Ti in the cubic phase includes a significant static component which means that Ti atoms are statistically distributed in the off-center positions. PMID:26830807

  14. Thermodynamics of NaCl in steam

    SciTech Connect

    Pitzer, K.S.; Pabalan, R.T.

    1986-07-01

    On the basis of the statistical mechanics of a two-component imperfect gas, a successive hydration model is developed for the NaCl ion-pair molecule in steam which fits satisfactorily an extensive array of experimental solubility data including the measurements of Bischoff et al. at the three-phase pressure from 300/sup 0/ to 503/sup 0/C and other concordant measurements extending to 600/sup 0/C at 290 bars. Some published experimental results depart substantially from the concordant set here selected. The theoretical basis of this model should make it useful for estimates at higher temperatures provided the mean hydration number and the total fluid density remain within the range corresponding to the fitted data. The measurements of Bodnar et al. at 500 bars and 800/sup 0/ and 825/sup 0/C provide a test and the agreement with model predictions is good.

  15. An Application of Specific Sensors For The Monitoring of NaCl in Soft Cheeses

    NASA Astrophysics Data System (ADS)

    Lvova, Larisa; Mielle, Patrick; Salles, Christian; Denis, Sylvain; Vergoignan, Catherine; Barra, Aurélien; Di Natale, Corrado; Paolesse, Roberto; Temple-Boyer, Pierre; Feron, Gilles

    2011-09-01

    The commercial sensors and prototype ISEs array (Ion Selective Electrodes array) were utilized for NaCl concentration measurements in soft cheeses, in particular in vitro gut process and in commercial Italian mozzarella cheeses. The values obtained from the sensors were compared with HPLC analysis. The results showed the feasibility of the ISE array application to monitor NaCl in soft cheese during the breakdown in the digester. The best results were obtained with the use of ISEs array combining, in particular, Cl- and Na+ detections. The salinity of commercial mozzarella cheese samples and the originally utilized milk type (cow or buffalo) were also satisfactory determined with the developed ISE array.

  16. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  17. Gaussian-type light bullet solutions of the (3+1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in PT-symmetric potentials

    SciTech Connect

    Zhu, Hai-Ping; Dai, Chao-Qing

    2014-12-15

    Two kinds of Gaussian-type light bullet (LB) solutions of the (3+1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in PT-symmetric potentials are analytically obtained. The phase switches, powers and transverse power-flow densities of these solutions in homogeneous media are studied. The linear stability analysis of these LB solutions and the direct numerical simulation indicate that LB solutions are stable below some thresholds for the imaginary part of PT-symmetric potentials in the defocusing cubic and focusing power-law nonlinear medium, while they are always unstable for all parameters in other media. Moreover, the broadened and compressed behaviors of LBs in the exponential periodic amplification system and diffraction decreasing system are discussed. Results indicate that LB is more stable for the sign-changing nonlinearity in the exponential periodic amplification system than for the non-sign-changing nonlinearity in the diffraction decreasing system at the same propagation distances.

  18. The effect of urea on the morphology of NaCl crystals: A combined theoretical and simulation study

    PubMed Central

    Smith, Paul E.

    2009-01-01

    It has been known for over a century that the presence of cosolvents such as urea and formamide can alter the morphology of NaCl crystals grown from solution. To help understand this effect we have been developing a theoretical approach based on the Kirkwood-Buff (KB) theory of solutions, and have combined this with computer simulations of the interation of urea with different crystal faces of NaCl. In this way one can predict the effect of urea on the thermodynamic stability of different NaCl faces, with atomic level detail provided by the simulations. We observe that urea is preferentially excluded from 100 and 111 crystal faces, but is less excluded from 111 faces which present chloride ions at the surface. The results indicate that the 111 face is stabilized in urea solutions and promotes the formation of octahedral over cubic NaCl crystals. The approach is totally general and can be applied to understand a variety of interfacial properties. Furthermore, we apply KB theory to study several other issues regarding the simulation of crystal growth. PMID:20383314

  19. Modified electrodes based on lipidic cubic phases.

    PubMed

    Bilewicz, Renata; Rowiński, Paweł; Rogalska, Ewa

    2005-04-01

    The lipidic cubic phase can be characterized as a curved bilayer forming a three-dimensional, crystallographical, well-ordered structure that is interwoven by aqueous channels. It provides a stable, well-organized environment in which diffusion of both water-soluble and lipid-soluble compounds can take place. Cubic phases based on monoacylglycerols form readily and attract our interest due to their ability to incorporate and stabilize proteins. Their lyotropic and thermotropic phase behaviour has been thoroughly investigated. At hydration over 20%, lipidic cubic phases Ia3d and Pn3m are formed. The latter is stable in the presence of excess water, which is important when the cubic phase is considered as an electrode-modifying material. Due to high viscosity, the cubic phases can be simply smeared over solid substrates such as electrodes and used to host enzymes and synthetic catalysts, leading to new types of catalytically active modified electrodes as shown for the determination of cholesterol, CO(2), or oxygen. The efficiency of transport of small hydrophilic molecules within the film can be determined by voltametry using two types of electrodes: a normal-size electrode working in the linear diffusion regime, and an ultramicroelectrode working under spherical diffusion conditions. This allows determining both the concentration and diffusion coefficient of the electrochemically active probe in the cubic phase. The monoolein-based cubic phase matrices are useful for immobilizing enzymes on the electrode surface (e.g., laccases from Trametes sp. and Rhus vernicifera were employed for monitoring dioxygen). The electronic contact between the electrode and the enzyme was maintained using suitable electroactive probes. PMID:15833697

  20. Cubic-normal distribution

    NASA Astrophysics Data System (ADS)

    Peng, Gan Chew; Hin, Pooi Ah; Ho, C. K.

    2015-12-01

    The power-normal distribution given in Yeo and Johnson in year 2000 is a unimodal distribution with wide ranges of skewness and kurtosis. A shortcoming of the power-normal distribution is that the negative and positve parts of the underlying random variable have to be specified by two different expressions of the standard normal random variable. In this paper, we construct a new distribution, called the cubic-normal distribution, via a single polynomial expression in cubic root function. Apart from having the properties which are similar to those of the power-normal distribution, this cubic-normal distribution can be developed into a multivariate version which is more attractive from the theoretical and computational points of view.

  1. Dissociation of methane hydrate in aqueous NaCl solutions.

    PubMed

    Yagasaki, Takuma; Matsumoto, Masakazu; Andoh, Yoshimichi; Okazaki, Susumu; Tanaka, Hideki

    2014-10-01

    Molecular dynamics simulations of the dissociation of methane hydrate in aqueous NaCl solutions are performed. It is shown that the dissociation of the hydrate is accelerated by the formation of methane bubbles both in NaCl solutions and in pure water. We find two significant effects on the kinetics of the hydrate dissociation by NaCl. One is slowing down in an early stage before bubble formation, and another is swift bubble formation that enhances the dissociation. These effects arise from the low solubility of methane in NaCl solution, which gives rise to a nonuniform spatial distribution of solvated methane in the aqueous phase. We also demonstrate that bubbles form near the hydrate interface in dense NaCl solutions and that the hydrate dissociation proceeds inhomogeneously due to the bubbles. PMID:25237735

  2. Cubic nitride templates

    DOEpatents

    Burrell, Anthony K; McCleskey, Thomas Mark; Jia, Quanxi; Mueller, Alexander H; Luo, Hongmei

    2013-04-30

    A polymer-assisted deposition process for deposition of epitaxial cubic metal nitride films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures under a suitable atmosphere to yield metal nitride films and the like. Such films can be used as templates for the development of high quality cubic GaN based electronic devices.

  3. Structure and properties of rhombohedral CePd{SUB 3}Ga{sub 8} : a variant of the cubic parent compound with BaHg{sub 11} structure type.

    SciTech Connect

    Macaluso, R. T.; Francisco, M.; Kanatzidis, M. G.; Young, D. P.; Stadler, S.; Mitchell, J. F.; Geiser, U.; Hong, H-Y.

    2011-01-01

    Single crystals of a new intermetallic gallide, R-CePd{sub 3}Ga{sub 8}, have been synthesized from excess molten gallium. Single-crystal X-ray diffraction reveals that R-CePd{sub 3}Ga{sub 8} crystallizes in the R-3m space group with a=b=c=8.4903(10) {angstrom} and {alpha}={beta}={gamma}=89.993(17). R-CePd{sub 3}Ga{sub 8} is a variant of the cubic BaHg{sub 11} structure type with three structural units: a Ce-centered polyhedron, a distorted cube of Pd{sub 2}Ga{sub 6} and a Pd-centered cuboctahedron. The distortions of these units are compared to a undistorted analogous units in intermetallic compounds with BaHg{sub 11} structure type. Field and temperature-dependent magnetization measurements on R-CePd{sub 3}Ga{sub 8} reveal a paramagnetic material with strong antiferromagnetic correlations and a magnetization consistent with Ce{sup 3+}. Electrical resistance measurements indicate Kondo behavior between localized Ce{sup 3+} magnetic moments.

  4. Effect of ENaC modulators on rat neural responses to NaCl.

    PubMed

    Mummalaneni, Shobha; Qian, Jie; Phan, Tam-Hao T; Rhyu, Mee-Ra; Heck, Gerard L; DeSimone, John A; Lyall, Vijay

    2014-01-01

    The effects of small molecule ENaC activators N,N,N-trimethyl-2-((4-methyl-2-((4-methyl-1H-indol-3-yl)thio)pentanoyl)oxy)ethanaminium iodide (Compound 1) and N-(2-hydroxyethyl)-4-methyl-2-((4-methyl-1H-indol-3-yl)thio)pentanamide (Compound 2), were tested on the benzamil (Bz)-sensitive NaCl chorda tympani (CT) taste nerve response under open-circuit conditions and under ±60 mV applied lingual voltage-clamp, and compared with the effects of known physiological activators (8-CPT-cAMP, BAPTA-AM, and alkaline pH), and an inhibitor (ionomycin+Ca2+) of ENaC. The NaCl CT response was enhanced at -60 mV and suppressed at +60 mV. In every case the CT response (r) versus voltage (V) curve was linear. All ENaC activators increased the open-circuit response (ro) and the voltage sensitivity (κ, negative of the slope of the r versus V curve) and ionomycin+Ca2+ decreased ro and κ to zero. Compound 1 and Compound 2 expressed a sigmoidal-saturating function of concentration (0.25-1 mM) with a half-maximal response concentration (k) of 0.49 and 1.05 mM, respectively. Following treatment with 1 mM Compound 1, 8-CPT-cAMP, BAPTA-AM and pH 10.3, the Bz-sensitive NaCl CT response to 100 mM NaCl was enhanced and was equivalent to the Bz-sensitive CT response to 300 mM NaCl. Plots of κ versus ro in the absence and presence of the activators or the inhibitor were linear, suggesting that changes in the affinity of Na+ for ENaC under different conditions are fully compensated by changes in the apical membrane potential difference, and that the observed changes in the Bz-sensitive NaCl CT response arise exclusively from changes in the maximum CT response (rm). The results further suggest that the agonists enhance and ionomycin+Ca2+ decreases ENaC function by increasing or decreasing the rate of release of Na+ from its ENaC binding site to the receptor cell cytosol, respectively. Irrespective of agonist type, the Bz-sensitive NaCl CT response demonstrated a maximum response enhancement

  5. Accurate thermoelastic tensor and acoustic velocities of NaCl

    SciTech Connect

    Marcondes, Michel L.; Shukla, Gaurav; Silveira, Pedro da; Wentzcovitch, Renata M.

    2015-12-15

    Despite the importance of thermoelastic properties of minerals in geology and geophysics, their measurement at high pressures and temperatures are still challenging. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy, approximations used in calculations of vibrational effects, and numerical/methodological approximations, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a method to improve the calculated thermoelastic tensor by using highly accurate thermal equation of state (EoS). The corrective scheme is general, applicable to crystalline solids with any symmetry, and can produce accurate results at conditions where experimental data may not exist. We apply it to rock-salt-type NaCl, a material whose structural properties have been challenging to describe accurately by standard ab initio methods and whose acoustic/seismic properties are important for the gas and oil industry.

  6. Accurate thermoelastic tensor and acoustic velocities of NaCl

    NASA Astrophysics Data System (ADS)

    Marcondes, Michel L.; Shukla, Gaurav; da Silveira, Pedro; Wentzcovitch, Renata M.

    2015-12-01

    Despite the importance of thermoelastic properties of minerals in geology and geophysics, their measurement at high pressures and temperatures are still challenging. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy, approximations used in calculations of vibrational effects, and numerical/methodological approximations, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a method to improve the calculated thermoelastic tensor by using highly accurate thermal equation of state (EoS). The corrective scheme is general, applicable to crystalline solids with any symmetry, and can produce accurate results at conditions where experimental data may not exist. We apply it to rock-salt-type NaCl, a material whose structural properties have been challenging to describe accurately by standard ab initio methods and whose acoustic/seismic properties are important for the gas and oil industry.

  7. NaCl Taste Thresholds in 13 Inbred Mouse Strains

    PubMed Central

    Ishiwatari, Yutaka

    2012-01-01

    Molecular mechanisms of salty taste in mammals are not completely understood. We use genetic approaches to study these mechanisms. Previously, we developed a high-throughput procedure to measure NaCl taste thresholds, which involves conditioning mice to avoid LiCl and then examining avoidance of NaCl solutions presented in 48-h 2-bottle preference tests. Using this procedure, we measured NaCl taste thresholds of mice from 13 genealogically divergent inbred stains: 129P3/J, A/J, BALB/cByJ, C3H/HeJ, C57BL/6ByJ, C57BL/6J, CBA/J, CE/J, DBA/2J, FVB/NJ, NZB/BlNJ, PWK/PhJ, and SJL/J. We found substantial strain variation in NaCl taste thresholds: mice from the A/J and 129P3/J strains had high thresholds (were less sensitive), whereas mice from the BALB/cByJ, C57BL/6J, C57BL/6ByJ, CE/J, DBA/2J, NZB/BINJ, and SJL/J had low thresholds (were more sensitive). NaCl taste thresholds measured in this study did not significantly correlate with NaCl preferences or amiloride sensitivity of chorda tympani nerve responses to NaCl determined in the same strains in other studies. To examine whether strain differences in NaCl taste thresholds could have been affected by variation in learning ability or sensitivity to toxic effects of LiCl, we used the same method to measure citric acid taste thresholds in 4 inbred strains with large differences in NaCl taste thresholds but similar acid sensitivity in preference tests (129P3/J, A/J, C57BL/6J, and DBA/2J). Citric acid taste thresholds were similar in these 4 strains. This suggests that our technique measures taste quality–specific thresholds that are likely to represent differences in peripheral taste responsiveness. The strain differences in NaCl taste sensitivity found in this study provide a basis for genetic analysis of this phenotype. PMID:22293936

  8. Stomatal and Nonstomatal Components to Inhibition of Photosynthesis in Leaves of Capsicum annuum during Progressive Exposure to NaCl Salinity 1

    PubMed Central

    Bethke, Paul C.; Drew, Malcolm C.

    1992-01-01

    Young bell pepper (Capsicum annuum L.) plants grown in nutrient solution were gradually acclimated to 50, 100, or 150 moles per cubic meter NaCl, and photosynthetic rates of individual attached leaves were measured on several occasions during the salinization period at external CO2 concentrations ranging from approximately 70 to 1900 micromoles per mole air. Net CO2 assimilation (A) was plotted against computed leaf internal CO2 concentration (Ci), and the initial slope of this A-Ci curve was used as a measure of photosynthetic ability. During the 10 to 14 days after salinization began, leaves from plants exposed to 50 moles per cubic meter NaCl showed little change in photosynthetic ability, whereas those treated to 100 or 150 moles per cubic meter NaCl had up to 85% inhibition, with increase in CO2 compensation point. Leaves appeared healthy, and leaf chlorophyll content showed only a 14% reduction at the highest salinity levels. Partial stomatal closure occurred with salinization, but reductions in photosynthesis were primarily nonstomatal in origin. Photosynthetic ability was inversely related to the concentration of either Na+ or Cl− in the leaf laminas sampled at the end of the experimental period. However, the concentration of Cl− expressed on a tissue water basis was greater, exceeding 300 moles per cubic meter, and Cl− was more closely associated (R2 = 0.926) with the inhibition of photosynthetic ability. Leaf turgor was not reduced by salinization and leaf osmotic potential decreased to a slightly greater extent than the osmotic potential decreases of the nutrient solutions. Concentration of accumulated Na+ and Cl− (on a tissue water basis) accounted quantitatively for maintenance of leaf osmotic balance, assuming that these ions were sequestered in the vacuoles. PMID:16668853

  9. PTCDA on Cu(111) partially covered with NaCl.

    PubMed

    Karacuban, H; Koch, S; Fendrich, M; Wagner, Th; Möller, R

    2011-07-22

    The organic molecule 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) was studied by means of scanning tunneling microscopy (STM) on thin insulating NaCl films grown on a Cu(111) single crystal. The deposition of approximately two monolayers (ML) of sodium chloride onto a Cu(111) substrate at a sample temperature of about 350 K causes a rather rough growth of (100)-oriented NaCl islands up to a local height of 4 ML. For submonolayer coverages (0.1 and 0.4 ML) of PTCDA on a Cu(111) surface partly covered with NaCl, two different rod structures of PTCDA were found on the copper surface, which are in contrast to previously published data for PTCDA on Cu(111) showing a herringbone-like arrangement. These findings can be explained by the formation of a Na(x)-PTCDA complex. On NaCl covered areas, single PTCDA molecules adsorb at vacancies of [010] and [001] oriented steps of the NaCl(100) islands. In this case, the electrostatic forces between the polar step edges and the PTCDA molecules are dominant. The terraces of the alkali halide surface are free of PTCDA molecules. PMID:21693798

  10. Growth and characterization of cubic and non-cubic Ge nanocrystals

    NASA Astrophysics Data System (ADS)

    Mukherjee, S.; Pradhan, A.; Mukherjee, S.; Maitra, T.; Nayak, A.; Bhunia, S.

    2016-05-01

    Germanium nanocrystals with tetragonal (ST-12) and diamond like cubic (Ge-I) phases have been selectively grown by controlling the ionization and electrostatic potential of Ge clusters in an ion cluster beam deposition system. Predominantly tetragonal nanocrystals were obtained when grown using neutral clusters. The percentage of cubic phase increased when grown by ionizing the clusters and accelerating them towards substrates by applying electrostatic bias in the range of 1.5 -2.5 kV. Raman spectroscopic measurement showed strong peak at 275 cm-1 and 300 cm-1 for tetragonal and cubic Ge nanocrystals, respectively. TEM measurements showed crystalline lattice fringes of both type of the nanocrystals. The selected area electron diffraction patterns showed (111) and (210) as the dominating lattice planes for tetragonal nanocrystals while the cubic phases had (111), (311) and (331) as the prominent lattice planes. The optical absorption edge redshifted from 1.75 to 1.55 eV as the percentage of the cubic phases increased in the NC composition in the composite film.

  11. Reversible wetting of NaCl nanoparticles at relative humidities below deliquescence observed by environmental non-contact AFM

    SciTech Connect

    Bruzewicz, D.A.; Lewis, E.; Ocko, B. M.; McGraw, R. L.; Schwartz, S. E.

    2009-12-14

    The behavior of NaCl nanoparticles as a function of relative humidity (RH) was characterized by depositing particles on a prepared hydrophobic surface and measuring their height via non-contact environmental atomic force microscopy (AFM). Non-contact AFM allows greater sensitivity to changes in the size of particles than does contact AFM or scanning electron microscopy, and greater sensitivity to changes in shape than do mass-based techniques. Crystalline cubic NaCl nanoparticles with sides of 35 to 150 nm were found to reversibly take up water with increasing RH, and to form a liquid-like surface layer of thickness 2 to 4 nm at humidities well below the deliquescence point of 75.0% at 20°C. Measurable uptake begins at 70% RH. The maximum thickness of the layer increases with increasing RH for a given particle size and, for a given RH, increases with increasing particle size over the range studied. The liquid-like behavior of the layer is indicated by a reversible “rounding” at the tops of the particles, where the ratio of particle height to radius of curvature increases from zero (flat top) at 68% RH to 0.7 at 74% RH. These observations suggest that a reorganization of mass occurs on the solid NaCl nanoparticle, and hence that the behavior of NaCl aerosol nanoparticles at RH between 70 and 75% RH is more complex than an abrupt first-order phase transition. Theoretical treatments of the phase transition should therefore account for both the presence of a liquid-like layer prior to deliquescence, and the RH-dependent thickness of the layer.

  12. Growth and electronic properties of NaCl on HOPG

    NASA Astrophysics Data System (ADS)

    Mahapatra, O.; Kowalczyk, P. J.; Brown, S. A.

    2014-02-01

    We report the growth of cross-shaped islands of NaCl on highly oriented pyrolytic graphite (HOPG) and discuss the mechanism of formation and growth kinetics within the framework of diffusion limited aggregation (DLA). These structures are investigated using scanning probe microscopy. The shape and structure of these islands can be finely controlled by the deposition conditions. The islands exhibit large atomically flat surfaces which are ideal supports for investigations of the fundamental properties of deposited atoms, molecules or clusters. Bismuth nanostructures were deposited on the NaCl islands and were investigated via scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). The tunneling spectra recorded for particles on NaCl are surprisingly similar to those measured for similar particles on HOPG. We suggest that this is due to a 'dead' layer commonly observed for Bi thin films.

  13. Radiation damage in NaCl. IV. Raman scattering

    SciTech Connect

    Groote, J.C.; Weerkamp, J.R.W.; Seinen, J.; den Hartog, H.W. )

    1994-10-01

    Raman-scattering experiments on heavily irradiated pure and doped NaCl crystals are described. The experiments have been performed at room temperature and at approximately 25 K. The crystals had been irradiated up to a maximum dose of 95 Grad by means of electrons from a Van de Graaff accelerator. The Raman spectra show the set of phonon peaks corresponding to the NaCl modes. At low frequencies the reduced Raman intensity shows a clear power-law dependence on the frequency, [ital I][sub red]([omega])[proportional to][omega][sup [nu

  14. Supercooling of aqueous NaCl and KCl solutions under acoustic levitation.

    PubMed

    Lü, Y J; Wei, B

    2006-10-14

    The supercooling capability of aqueous NaCl and KCl solutions is investigated at containerless state by using acoustic levitation method. The supercooling of water is obviously enhanced by the alkali metal ions and increases linearly with the augmentation of concentrations. Furthermore, the supercooling depends on the nature of ions and is 2-3 K larger for NaCl solution than that for KCl solution in the present concentration range: Molecular dynamics simulations are performed to reveal the intrinsic correlation between supercoolability and microstructure. The translational and orientational order parameters are applied to quantitatively demonstrate the effect of ionic concentration on the hydrogen-bond network and ice melting point. The disrupted hydrogen-bond structure determines essentially the concentration dependence of supercooling. On the other hand, the introduced acoustic pressure suppresses the increase of supercooling by promoting the growth and coalescence of microbubbles, the effective nucleation catalysts, in water. However, the dissolved ions can weaken this effect, and moreover the degree varies with the ion type. This results in the different supercoolability for NaCl and KCl solutions under the acoustic levitation conditions. PMID:17042605

  15. Reversible uptake of water on NaCl nanoparticles at relative humidity below deliquescence point observed by noncontact environmental atomic force microscopy.

    PubMed

    Bruzewicz, Derek A; Checco, Antonio; Ocko, Benjamin M; Lewis, Ernie R; McGraw, Robert L; Schwartz, Stephen E

    2011-01-28

    The behavior of NaCl nanoparticles as a function of relative humidity (RH) has been characterized using non-contact environmental atomic force microscopy (e-AFM) to measure the heights of particles deposited on a prepared hydrophobic surface. Cubic NaCl nanoparticles with sides of 35 and 80 nm were found to take up water reversibly with increasing RH well below the bulk deliquescence relative humidity (DRH) of 75% at 23(∘)C, and to form a liquid-like surface layer of thickness 2 to 5 nm, with measurable uptake (>2 nm increase in particle height) beginning at 70% RH. The maximum thickness of the layer increased with increasing RH and increasing particle size over the range studied. The liquid-like behavior of the layer was indicated by a reversible rounding at the upper surface of the particles, fit to a parabolic cross-section, where the ratio of particle height to maximum radius of curvature increases from zero (flat top) at 68% RH to 0.7 ± 0.3 at 74% RH. These observations, which are consistent with a reorganization of mass on the solid NaCl nanocrystal at RH below the DRH, suggest that the deliquescence of NaCl nanoparticles is more complex than an abrupt first-order phase transition. The height measurements are consistent with a phenomenological model that assumes favorable contributions to the free energy of formation of a liquid layer on solid NaCl due both to van der Waals interactions, which depend partly upon the Hamaker constant, A(film), of the interaction between the thin liquid film and the solid NaCl, and to a longer-range electrostatic interaction over a characteristic length of persistence, ξ; the best fit to the data corresponded to A(film)= 1 kT and ξ = 2.33 nm. PMID:21280780

  16. Ultraweak bioluminescence of maize under NaCl stress

    NASA Astrophysics Data System (ADS)

    Xie, Zhaohui

    2009-11-01

    In this paper, the delayed ultra-weak luminescence (UWL), leaf dry/fresh weight and reactive oxygen species (ROS) of the maize (Jundan 20) were investigated under various NaCl concentration. The results showed that following with the increase of NaCl, ROS contents increased obviously, but the UWL intensity decreased, and the decrease speed increased following with the increase of NaCl concentration, the decrease extent of delayed luminescence ranged from 10.4% to 27.2%. It was also found that both dry and fresh weight of seedling leaves decreased, but the ratio of dry/fresh weight increased. According to these results, we speculated that the decrease of UWL was mainly closely associated with the destruction of seedling normal physiological activities and metabolic disorder which were caused by NaCl stress, rather than ROS only. This study revealed that the spectral analysis of UWL is a useful tool for studying plant response to salt stress.

  17. Substituting KCl for NaCl in fresh Queso Fresco

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing the sodium level in cheese is challenging when a signature salty flavor is expected, such as in high-moisture Queso Fresco (QF). Fresh starter-free QF was fine milled and dry salted at different levels of NaCl and KCl to obtain total salt levels of 1.5 to 2.0%. The treatments contained 1....

  18. Critical behavior of dilute NaCl in H2O

    USGS Publications Warehouse

    Pitzer, Kenneth S.; Bischoff, J.L.; Rosenbauer, R.J.

    1987-01-01

    The compositions of the saturated vapor and liquid phases are measured for the system NaCl-H2O at 380??C, which is close to the critical point of pure water. The shape of the phase equilibrium curve is classical, which confirms a conclusion reached earlier on the basis of less accurate data. This implies that the long-range forces introduced by the NaCl suppress the non-classical effects present in pure H2O. An empirical equation of a classical type fits these data. ?? 1987.

  19. Interfacial free energy of the NaCl crystal-melt interface from capillary wave fluctuations.

    PubMed

    Benet, Jorge; MacDowell, Luis G; Sanz, Eduardo

    2015-04-01

    In this work we study, by means of molecular dynamics simulations, the solid-liquid interface of NaCl under coexistence conditions. By analysing capillary waves, we obtain the stiffness for different orientations of the solid and calculate the interfacial free energy by expanding the dependency of the interfacial free energy with the solid orientation in terms of cubic harmonics. We obtain an average value for the solid-fluid interfacial free energy of 89 ± 6 mN m(-1) that is consistent with previous results based on the measure of nucleation free energy barriers [Valeriani et al., J. Chem. Phys. 122, 194501 (2005)]. We analyse the influence of the simulation setup on interfacial properties and find that facets prepared as an elongated rectangular stripe give the same results as those prepared as squares for all cases but the 111 face. For some crystal orientations, we observe at small wave-vectors a behaviour not consistent with capillary wave theory and show that this behavior does not depend on the simulation setup. PMID:25854257

  20. First principles molecular dynamics of molten NaCl

    NASA Astrophysics Data System (ADS)

    Galamba, N.; Costa Cabral, B. J.

    2007-03-01

    First principles Hellmann-Feynman molecular dynamics (HFMD) results for molten NaCl at a single state point are reported. The effect of induction forces on the structure and dynamics of the system is studied by comparison of the partial radial distribution functions and the velocity and force autocorrelation functions with those calculated from classical MD based on rigid-ion and shell-model potentials. The first principles results reproduce the main structural features of the molten salt observed experimentally, whereas they are incorrectly described by both rigid-ion and shell-model potentials. Moreover, HFMD Green-Kubo self-diffusion coefficients are in closer agreement with experimental data than those predicted by classical MD. A comprehensive discussion of MD results for molten NaCl based on different ab initio parametrized polarizable interionic potentials is also given.

  1. New cubic phase of lithium nitride to 200 GPa

    SciTech Connect

    Lazicki, A; Maddox, B; Evans, W; Yoo, C S; McMahan, A K; Pickett, W E; Scalettar, R T; Hu, M Y; Chow, P

    2005-07-19

    We present a new cubic ({gamma}) Li{sub 3}N phase discovered above 40({+-}5) GPa. Structure and electronic bands are examined at high pressure with synchrotron x-ray diffraction and inelastic x-ray scattering in a diamond anvil cell, and also with first-principles calculations. We observe a dramatic band-gap widening and volume collapse at the phase transition. {gamma}-Li{sub 3}N remains extremely stable and ionic to 200 GPa, with predicted metallization near 8 TPa. The high structural stability, wide band-gap and simple electronic structure of {gamma}-Li{sub 3}N are analogous to that of such lower valence closed-shell solids as NaCl, MgO and Ne, meriting its use as a low-Z internal pressure standard.

  2. Inhibition of nitrate reduction by NaCl adsorption on a nano-zero-valent iron surface during a concentrate treatment for water reuse.

    PubMed

    Hwang, Yuhoon; Kim, Dogun; Shin, Hang-Sik

    2015-01-01

    Nanoscale zero-valent iron (NZVI) has been considered as a possible material to treat water and wastewater. However, it is necessary to verify the effect of the matrix components in different types of target water. In this study, different effects depending on the sodium chloride (NaCl) concentration on reductions of nitrates and on the characteristics of NZVI were investigated. Although NaCl is known as a promoter of iron corrosion, a high concentration of NaCl (>3 g/L) has a significant inhibition effect on the degree of NZVI reactivity towards nitrate. The experimental results were interpreted by a Langmuir-Hinshelwood-Hougen-Watson reaction in terms of inhibition, and the decreased NZVI reactivity could be explained by the increase in the inhibition constant. As a result of a chloride concentration analysis, it was verified that 7.7-26.5% of chloride was adsorbed onto the surface of NZVI. Moreover, the change of the iron corrosion product under different NaCl concentrations was investigated by a surface analysis of spent NZVI. Magnetite was the main product, with a low NaCl concentration (0.5 g/L), whereas amorphous iron hydroxide was observed at a high concentration (12 g/L). Though the surface was changed to permeable iron hydroxide, the Fe(0) in the core was not completely oxidized. Therefore, the inhibition effect of NaCl could be explained as the competitive adsorption of chloride and nitrate. PMID:25358487

  3. Relationship between NaCl- and H2O2-Induced Cytosolic Ca2+ Increases in Response to Stress in Arabidopsis

    PubMed Central

    Ye, Rui; Xue, Yan; Chen, Amelia; An, Lizhe; Pei, Zhen-Ming

    2013-01-01

    Salinity is among the environmental factors that affect plant growth and development and constrain agricultural productivity. Salinity stress triggers increases in cytosolic free Ca2+ concentration ([Ca2+]i) via Ca2+ influx across the plasma membrane. Salinity stress, as well as other stresses, induces the production of reactive oxygen species (ROS). It is well established that ROS also triggers increases in [Ca2+]i. However, the relationship and interaction between salinity stress-induced [Ca2+]i increases and ROS-induced [Ca2+]i increases remain poorly understood. Using an aequorin-based Ca2+ imaging assay we have analyzed [Ca2+]i changes in response to NaCl and H2O2 treatments in Arabidopsis thaliana. We found that NaCl and H2O2 together induced larger increases in [Ca2+]i in Arabidopsis seedlings than either NaCl or H2O2 alone, suggesting an additive effect on [Ca2+]i increases. Following a pre-treatment with either NaCl or H2O2, the subsequent elevation of [Ca2+]i in response to a second treatment with either NaCl or H2O2 was significantly reduced. Furthermore, the NaCl pre-treatment suppressed the elevation of [Ca2+]i seen with a second NaCl treatment more than that seen with a second treatment of H2O2. A similar response was seen when the initial treatment was with H2O2; subsequent addition of H2O2 led to less of an increase in [Ca2+]i than did addition of NaCl. These results imply that NaCl-gated Ca2+ channels and H2O2-gated Ca2+ channels may differ, and also suggest that NaCl- and H2O2-evoked [Ca2+]i may reduce the potency of both NaCl and H2O2 in triggering [Ca2+]i increases, highlighting a feedback mechanism. Alternatively, NaCl and H2O2 may activate the same Ca2+ permeable channel, which is expressed in different types of cells and/or activated via different signaling pathways. PMID:24124535

  4. Atmospheric Corrosion of Ag and Cu with Ozone, UV and NaCl

    NASA Astrophysics Data System (ADS)

    Lin, Huang

    Ag and Cu are both used for electronics and are susceptible to atmospheric corrosion. They are also good corrosivity monitors used to evaluate aggressiveness of the environment. Unfortunately, laboratory exposure testing does not always represent field environments very well. Discrepancies between lab and field exposure tests are not uncommon. For example, Ag does not corrode in salt spray exposure during ASTM B117 test, while it corrodes everywhere outdoor. This suggests that new laboratory exposure test for Ag needs to be designed and studied. A full factorial experiment was carried out with three factors: ozone, UV intensity and relative humidity (RH). NaCl was loaded by fast evaporation of NaCl/ethanol solution before exposure. After exposure, corrosion products were identified by XRD and quantified by galvanostatic reduction technique. For lab exposure samples, AgCl was identified as the only corrosion product in high RH (87%) environments, while Ag2O and AgO formed as well during exposures at low RH. This result derived a qualitative prediction on corrosion behavior of Ag in field. It predicts that less stable silver compounds such as oxide and sulfate are possible corrosion products in field even silver chloride is the dominant corrosion product forming in field. This prediction was confirmed by analysis of field exposed Ag samples. By quantification of corrosion products, it is determined that UV has two contravening effects on atmospheric corrosion of Ag: photolysis of ozone to generate stronger oxidizing species such as atomic O and photodecomposition of Ag corrosion products by UV radiation. Following its success in Ag corrosion research, the environment of UV, ozone and NaCl was extended to study Cu corrosion. It is determined that UV alone can double Cu corrosion rate by generation of electron-hole pairs in n-type cuprous oxide. It is also found that ozone alone is not as aggressive on Ag as on Cu because protection of naturally formed cuprous oxide

  5. Covering surface nanobubbles with a NaCl nanoblanket.

    PubMed

    Berkelaar, Robin P; Zandvliet, Harold J W; Lohse, Detlef

    2013-09-10

    By letting a NaCl aqueous solution of low (0.01 M) concentration evaporate on a highly oriented pyrolytic graphite (HOPG) surface, it is possible to form a thin film of salt. However, pre-existing surface nanobubbles prevent the homogeneous coverage of the surface with the salt, keeping the footprint areas on the substrate pristine. Comparing the surface nanobubbles in the salt solution with their associated footprint after drying, provides information on the shrinkage of nanobubbles during the hours-long process of drying the liquid film. At a slightly higher NaCl concentration and thus salt layer thickness, the nanobubbles are covered with a thin blanket of salt. Once the liquid film has evaporated until a water film remains that is smaller than the height of the nanobubbles, the blanket of salt cracks and unfolds into a flower-like pattern of salt flakes that is located at the rim of the nanobubble footprint. The formation of a blanket of salt covering the nanobubbles is likely to considerably or even completely block the gas out-flux from the nanobubble, partially stabilizing the nanobubbles against dissolution. PMID:23937683

  6. Effects of Osmoprotectants upon NaCl Stress in Rice.

    PubMed Central

    Garcia, A. B.; Engler, JdA.; Iyer, S.; Gerats, T.; Van Montagu, M.; Caplan, A. B.

    1997-01-01

    Plants accumulate a number of osmoprotective substances in response to NaCl stress, one of them being proline (Pro). While characterizing some of the changes in solute accumulation in NaCl-stressed rice (Oryza sativa L.), we identified several other potential osmoprotectants. One such substance, trehalose, begins to accumulate in small amounts in roots after 3 d. We performed a series of experiments to compare the effects of Pro and trehalose on ion accumulation to determine whether the two chemicals protect the same physiological processes. We found that Pro either has no effect or, in some cases, exasperates the effect of NaCl on growth inhibition, chlorophyll loss, and induction of a highly sensitive marker for plant stress, the osmotically regulated salT gene. By contrast, low to moderate concentrations of trehalose reduce Na+ accumulation, salT expression, and growth inhibition. Somewhat higher concentrations (10 mM) prevent NaCl-induced loss of chlorophyll in blades, preserve root integrity, and enhance growth. The results of this study indicate that during osmotic stress trehalose or carbohydrates might be more important for rice than Pro. PMID:12223797

  7. Cubic Unit Cell Construction Kit.

    ERIC Educational Resources Information Center

    Mattson, Bruce

    2000-01-01

    Presents instructions for building a simple interactive unit-cell construction kit that allows for the construction of simple, body-centered, and face-centered cubic lattices. The lit is built from inexpensive and readily available materials and can be built in any number of sizes. (WRM)

  8. Cubication of Conservative Nonlinear Oscillators

    ERIC Educational Resources Information Center

    Belendez, Augusto; Alvarez, Mariela L.; Fernandez, Elena; Pascual, Immaculada

    2009-01-01

    A cubication procedure of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force, and this allows us to approximate the original nonlinear differential equation by a Duffing equation in which the coefficients for the linear…

  9. Compensation in epitaxial cubic SiC films

    NASA Technical Reports Server (NTRS)

    Segall, B.; Alterovitz, S. A.; Haugland, E. J.; Matus, L. G.

    1986-01-01

    Hall measurements on four n-type cubic SiC films epitaxially grown by chemical vapor deposition on SiC substrates are reported. The temperature dependent carrier concentrations indicate that the samples are highly compensated. Donor ionization energies, E sub D, are less than one half the values previously reported. The values for E sub D and the donor concentration N sub D, combined with results for small bulk platelets with nitrogen donors, suggest the relation E sub D (N sub D) = E sub D(O) - alpha N sub N sup 1/3 for cubic SiC. A curve fit gives alpha is approx 2.6x10/5 meV cm and E sub D (O) approx 48 meV, which is the generally accepted value of E sub D(O) for nitrogen donors in cubic SiC.

  10. Use of Pom Pons To Illustrate Cubic Crystal Structures

    NASA Astrophysics Data System (ADS)

    Cady, Susan G.

    1997-07-01

    In general chemistry classes, students are introduced to the ways in which atoms are arranged in cubic crystal structures. Transposing the textbook illustrations into three dimensional structures is difficult for some students. This transitions is easier if a three dimensional model is available for examination. Several 3D models are cited. A quick to assemble, inexpensive, colorful, and durable alternative to these models and styrofoam balls is the use of olefin pom pons. Different sized pom pons can be used to demonstrate how the atomic radius will vary when comparing the different types of cubic crystal unit cells. Being made of a coarse material, pom pons can be stacked to illustrate different packing arrangements such as hexagonal close-packed and cubic close-packed structures. Pom pons make great atoms.

  11. Solving Cubic Equations by Polynomial Decomposition

    ERIC Educational Resources Information Center

    Kulkarni, Raghavendra G.

    2011-01-01

    Several mathematicians struggled to solve cubic equations, and in 1515 Scipione del Ferro reportedly solved the cubic while participating in a local mathematical contest, but did not bother to publish his method. Then it was Cardano (1539) who first published the solution to the general cubic equation in his book "The Great Art, or, The Rules of…

  12. Estimating the hydrogen ion concentration in concentrated NaCl and Na{sub 2}SO{sub 4} electrolytes

    SciTech Connect

    Rai, D.; Felmy, A.R.; Juracich, S.P.; Rao, F.

    1995-06-01

    Combination glass electrodes were tested for determining H{sup +} concentrations in concentrated pure and mixed NaCl and Na{sub 2}SO{sub 4} solutions, as well as natural brine systems. NaCl, Na{sub 2}SO{sub 4}, and mixtures of NaCl and Na{sub 2}SO{sub 4} solutions were analyzed. Correction factors for estimating pC{sub H}{sup +} (negative logarithm of H{sup +} concentration) were determined from measured/observed pH values. Required Gran-type titrations were done with HCl and/or NaOH. The titration method is described and a step-by-step procedure provided; it has been used previously for determining pC{sub H}{sup +} values of synthetic chloride-dominated brines. Precautions are required to determine correction factors for electrolytes that react with H{sup +} or OH{sup {minus}} [sulfate brines for titration with acid; magnesium brines for titration with base because of precipitation of Mg(OH)2]. Correction factors A (pC{sub H}{sup +} = pH{sub ob} + A) from HCl titrations were similar to those from NaOH titrations where the concentration of free H{sup +} was calculated using a thermodynamic model. These values should be applicable to solns with a very large range in measured pH values (2 to 12). Because a large number of solns were titrated with HCl and the A values are similar for HCl and NaOH titrations, the A values for NaCl and Na2SO4 solns were fit as a function of molality to allow extrapolation. For NaCl solns 0 to 6.0 M, A can be obtained by multiplying the molality by 0.159. For Na2SO4 solns 0 to 2.0 M, the values of A can be obtained from (0.221 {minus} 0.549X + 0.201X{sup 2}), where X is the molality of Na{sub 2}SO{sub 4}. Orion-Ross electrode evaluations indicated that the A values did not differ significantly for different electrodes. Results suggest that the data in this report can be used to estimate A values for different NaCl and Na{sub 2}SO{sub 4} solns even for noncalibrated electrodes.

  13. Electrochemistry of selenium in a basic AlCl{sub 3}-NaCl melt

    SciTech Connect

    Matsunaga, M.; Morimitsu, M.; Hosokawa, K.

    1995-09-01

    Sodium/molten-salt secondary batteries composed of a liquid sodium and chloroaluminate melt have been widely studied for electric vehicle and load-leveling applications. The authors have been interested in developing new cathode materials to be used in this type of battery. The electrochemical reactions of selenium species in a basic AlCl{sub 3}-NaCl melt has been studied by measuring EMF of an Na/SeCl{sub 4} cell. The reaction mechanism between elemental and tetravalent selenium consists of at least four electrochemical steps, including intermediates such as Se{sup 2+}, Se{sub 2}{sup 2+}, and Se{sub 8}{sup 2+}. The reaction sequence from Se{sup 4+} to Se{sub 8}{sup 2+} is discussed. The formal potential for each reaction is also determined.

  14. The use of NaCl addition for the improvement of polyhydroxyalkanoate production by Cupriavidus necator.

    PubMed

    Passanha, Pearl; Kedia, Gopal; Dinsdale, Richard M; Guwy, Alan J; Esteves, Sandra R

    2014-07-01

    External stress factors in the form of ionic species or temperature increases have been shown to produce a stress response leading to enhanced PHA production. The effect of five different NaCl concentrations, namely 3.5, 6.5, 9, 12 and 15 g/l NaCl on PHA productivity using Cupriavidus necator has been investigated alongside a control (no added NaCl). A dielectric spectroscopy probe was used to measure PHA accumulation online in conjunction with the chemical offline analysis of PHA. The highest PHA production was obtained with the addition of 9 g/l NaCl, which yielded 30% higher PHA than the control. Increasing the addition of NaCl to 15 g/l was found to inhibit the production of PHA. NaCl addition can therefore be used as a simple, low cost, sustainable, non toxic and non reactive external stress strategy for increasing PHA productivity. PMID:24835740

  15. Nonlinear surface acoustic waves in cubic crystals

    NASA Astrophysics Data System (ADS)

    Kumon, Ronald Edward

    Model equations developed by Hamilton, Il'inskii, and Zabolotskaya [J. Acoust. Soc. Am. 105, 639-651 (1999)] are used to perform theoretical and numerical studies of nonlinear surface acoustic waves in a variety of nonpiezoelectric cubic crystals. The basic theory underlying the model equations is outlined, quasilinear solutions of the equations are derived, and expressions are developed for the shock formation distance and nonlinearity coefficient. A time-domain equation corresponding to the frequency-domain model equations is derived and shown to reduce to a time-domain equation introduced previously for Rayleigh waves [E. A. Zabolotskaya, J. Acoust. Soc. Am. 91, 2569-2575 (1992)]. Numerical calculations are performed to predict the evolution of initially monofrequency surface waves in the (001), (110), and (111) planes of the crystals RbCl, KCl, NaCl, CaF2, SrF2, BaF2, C (diamond), Si, Ge, Al, Ni, Cu in the moverline 3m point group, and the crystals Cs-alum, NH4- alum, and K-alum in the moverline 3 point group. The calculations are based on measured second- and third- order elastic constants taken from the literature. Nonlinearity matrix elements which describe the coupling strength of harmonic interactions are shown to provide a powerful tool for characterizing waveform distortion. Simulations in the (001) and (110) planes show that in certain directions the velocity waveform distortion may change in sign, generation of one or more harmonies may be suppressed and shock formation postponed, or energy may be transferred rapidly to the highest harmonics and shock formation enhanced. Simulations in the (111) plane show that the nonlinearity matrix elements are generally complex-valued, which may lead to asymmetric distortion and the appearance of low frequency oscillations near the peaks and shocks in the velocity waveforms. A simple transformation based on the phase of the nonlinearity matrix is shown to provide a reasonable approximation of asymmetric waveform

  16. Effect of NaCl, Gum Arabic and Microbial Transglutaminase on the Gel and Emulsion Characteristics of Porcine Myofibrillar Proteins

    PubMed Central

    Davaatseren, Munkhtugs

    2014-01-01

    This study investigated the effect of gum arabic (GA) combined with microbial transglutaminase (TG) on the functional properties of porcine myofibrillar protein (MP). As an indicator of functional property, heat-set gel and emulsion characteristics of MP treated with GA and/or TG were explored under varying NaCl concentrations (0.1-0.6 M). The GA improved thermal gelling ability of MP during thermal processing and after cooling, and concomitantly added TG assisted the formation of viscoelastic MP gel formation. Meanwhile, the addition of GA decreased cooking yield of MP gel at 0.6 M NaCl concentration, and the yield was further decreased by TG addition, mainly attributed by enhancement of protein-protein interactions. Emulsion characteristics indicated that GA had emulsifying ability and the addition of GA increased the emulsification activity index (EAI) of MP-stabilized emulsion. However, GA showed a negative effect on emulsion stability, particularly great drop in the emulsion stability index (ESI) was found in GA treatment at 0.6 M NaCl. Consequently, the results indicated that GA had a potential advantage to form a viscoelastic MP gel. For the practical aspect, the application of GA in meat processing had to be limited to the purposes of texture enhancer such as restructured products, but not low-salt products and emulsion-type meat products. PMID:26761678

  17. Natural variability in Drosophila larval and pupal NaCl tolerance.

    PubMed

    Riedl, Craig A L; Oster, Sara; Busto, Macarena; Mackay, Trudy F C; Sokolowski, Marla B

    2016-05-01

    The regulation of NaCl is essential for the maintenance of cellular tonicity and functionality, and excessive salt exposure has many adverse effects. The fruit fly, Drosophila melanogaster, is a good osmoregulator and some strains can survive on media with very low or high NaCl content. Previous analyses of mutant alleles have implicated various stress signaling cascades in NaCl sensitivity or tolerance; however, the genes influencing natural variability of NaCl tolerance remain for the most part unknown. Here, we use two approaches to investigate natural variation in D. melanogaster NaCl tolerance. We describe four D. melanogaster lines that were selected for different degrees of NaCl tolerance, and present data on their survival, development, and pupation position when raised on varying NaCl concentrations. After finding evidence for natural variation in salt tolerance, we present the results of Quantitative Trait Loci (QTL) mapping of natural variation in larval and pupal NaCl tolerance, and identify different genomic regions associated with NaCl tolerance during larval and pupal development. PMID:26874056

  18. Arbuscular mycorrhizal symbiosis and osmotic adjustment in response to NaCl stress: a meta-analysis

    PubMed Central

    Augé, Robert M.; Toler, Heather D.; Saxton, Arnold M.

    2014-01-01

    Arbuscular mycorrhizal (AM) symbiosis can enhance plant resistance to NaCl stress in several ways. Two fundamental roles involve osmotic and ionic adjustment. By stimulating accumulation of solutes, the symbiosis can help plants sustain optimal water balance and diminish Na+ toxicity. The size of the AM effect on osmolytes has varied widely and is unpredictable. We conducted a meta-analysis to determine the size of the AM effect on 22 plant solute characteristics after exposure to NaCl and to examine how experimental conditions have influenced the AM effect. Viewed across studies, AM symbioses have had marked effects on plant K+, increasing root and shoot K+ concentrations by an average of 47 and 42%, respectively, and root and shoot K+/Na+ ratios by 47 and 58%, respectively. Among organic solutes, soluble carbohydrates have been most impacted, with AM-induced increases of 28 and 19% in shoots and roots. The symbiosis has had no consistent effect on several characteristics, including root glycine betaine concentration, root or shoot Cl− concentrations, leaf Ψπ, or shoot proline or polyamine concentrations. The AM effect has been very small for shoot Ca++ concentration and root concentrations of Na+, Mg++ and proline. Interpretations about AM-conferred benefits regarding these compounds may be best gauged within the context of the individual studies. Shoot and root K+/Na+ ratios and root proline concentration showed significant between-study heterogeneity, and we examined nine moderator variables to explore what might explain the differences in mycorrhizal effects on these parameters. Moderators with significant impacts included AM taxa, host type, presence or absence of AM growth promotion, stress severity, and whether NaCl constituted part or all of the experimental saline stress treatment. Meta-regression of shoot K+/Na+ ratio showed a positive response to root colonization, and root K+/Na+ ratio a negative response to time of exposure to NaCl. PMID:25368626

  19. Characterization of NaCl tolerance in Desulfovibrio vulgaris Hildenborough through experimental evolution

    PubMed Central

    Zhou, Aifen; Baidoo, Edward; He, Zhili; Mukhopadhyay, Aindrila; Baumohl, Jason K; Benke, Peter; Joachimiak, Marcin P; Xie, Ming; Song, Rong; Arkin, Adam P; Hazen, Terry C; Keasling, Jay D; Wall, Judy D; Stahl, David A; Zhou, Jizhong

    2013-01-01

    Desulfovibrio vulgaris Hildenborough strains with significantly increased tolerance to NaCl were obtained via experimental evolution. A NaCl-evolved strain, ES9-11, isolated from a population cultured for 1200 generations in medium amended with 100 mM NaCl, showed better tolerance to NaCl than a control strain, EC3-10, cultured for 1200 generations in parallel but without NaCl amendment in medium. To understand the NaCl adaptation mechanism in ES9-11, we analyzed the transcriptional, metabolite and phospholipid fatty acid (PLFA) profiles of strain ES9-11 with 0, 100- or 250 mM-added NaCl in medium compared with the ancestral strain and EC3-10 as controls. In all the culture conditions, increased expressions of genes involved in amino-acid synthesis and transport, energy production, cation efflux and decreased expression of flagellar assembly genes were detected in ES9-11. Consistently, increased abundances of organic solutes and decreased cell motility were observed in ES9-11. Glutamate appears to be the most important osmoprotectant in D. vulgaris under NaCl stress, whereas, other organic solutes such as glutamine, glycine and glycine betaine might contribute to NaCl tolerance under low NaCl concentration only. Unsaturation indices of PLFA significantly increased in ES9-11. Branched unsaturated PLFAs i17:1 ω9c, a17:1 ω9c and branched saturated i15:0 might have important roles in maintaining proper membrane fluidity under NaCl stress. Taken together, these data suggest that the accumulation of osmolytes, increased membrane fluidity, decreased cell motility and possibly an increased exclusion of Na+ contribute to increased NaCl tolerance in NaCl-evolved D. vulgaris. PMID:23575373

  20. MAPK-mediated enhanced expression of vacuolar H(+)-ATPase confers the improved adaption to NaCl stress in a halotolerate peppermint (Mentha piperita L.).

    PubMed

    Li, Zhe; Zhen, Zhen; Guo, Kai; Harvey, Paul; Li, Jishun; Yang, Hetong

    2016-03-01

    Vacuolar H(+)-ATPase (V-H(+)-ATPase) has been proved to be of importance in maintenance of ion homeostasis inside plant cells under NaCl stress. In this study, the expression levels and salt-tolerate function of V-H(+)-ATPase genes were investigated in the roots and leaves of a halotolerate peppermint (Mentha × piperita L.) Keyuan-1 treated with different concentrations of NaCl. Results showed that the expressions of V-H(+)-ATPase in the transcriptional, protein and activity levels were significantly enhanced in the halotolerate peppermint Keyuan-1 compared to the wild-type (WT) peppermint under 50, 100, and 150 mM NaCl treatment. Moreover, inhibition experiments exhibited that V-H(+)-ATPase activity played vital roles in the salt tolerance of peppermint Keyuan-1 to 150 mM NaCl stress through increasing the vacuolar H(+) pumping activity and Na(+) compartmentalization capacity. Furthermore, results of Western blots showed that the activity of a mitogen-activated protein kinase (MAPK) was significantly increased under different concentrations of NaCl in the halotolerate peppermint Keyuan-1, which was much higher than that of WT peppermint. Further experiments with inhibitors suggested that this MAPK protein was responsible for the enhanced expression of V-H(+)-ATPase in the halotolerate peppermint Keyuan-1. In response to NaCl stress, increase of cytoplasmic calcium concentration ([Ca(2+)]cyt) occurred upstream of MAPK activation in the halotolerate peppermint Keyuan-1. In all, these findings demonstrated that increased V-H(+)-ATPase activity was positively correlated with the enhanced salt tolerance in the halotolerate peppermint Keyuan-1, providing the theoretic basis for the further development and utilization of peppermint in saline areas. PMID:25999237

  1. Genetic variability of NaCl tolerance in tomato.

    PubMed

    Saeed, A; Saleem, M F; Zakria, M; Anjum, S A; Shakeel, A; Saeed, N

    2011-01-01

    Cultivation of crops in soils with high salt (NaCl) content can affect plant development. We examined the morphological and physiological mechanisms of salt tolerance in tomato. The responses of 72 accessions of tomato (Solanum lycopersicum) to salinity were compared by measuring shoot and root lengths, and fresh shoot and root weights relative to those of controls (plants grown in normal salt levels). All traits were reduced at the seedling stage when salinity levels were increased. The accession x salinity interaction was significant for all traits. Root length had higher heritability than other traits and was used as a selection criterion to identify salt-tolerant and -non-tolerant accessions. On the basis of root length, accessions LA2661, CLN2498A, CLN1621L, BL1176, 6233, and 17870 were considered to be more tolerant than accessions 17902, LO2875 and LO4360. The degree of salt tolerance was checked by analyzing K+ and Na+ concentrations and K+/Na+ ratio in tissues of plants treated with 10 and 15 dS/m salinity levels. Tolerance of these accessions to salinity was most associated with low accumulation of Na+ and higher K+/Na+ ratios. PMID:21823086

  2. Eu2+-->Mn2+ energy transfer in NaCl

    NASA Astrophysics Data System (ADS)

    Rubio O., J.; Murrieta S., H.; Powell, R. C.; Sibley, W. A.

    1985-01-01

    Crystals of NaCl containing different concentrations of Eu2+ and Mn2+ ions (the Eu concentration always being less than that of Mn) were investigated by optical and EPR spectroscopy. The results show that Eu2+-Mn2+ pairs form preferentially in this material and that highly efficient energy transfer occurs from the Eu2+ ions to the near-neighbor Mn2+ ions. Over 99% of the Eu2+ ions are paired, and these pairs are not significantly affected by the state of aggregation of the Mn ions, although in the various samples evidence for manganese ions in their dipolar state, as well as precipitated into the Suzuki phase, exists. The excitation spectra of the orange manganese emission show, in addition to the Eu2+ 4f7-->4f65d transitions, Mn2+ transitions associated with the Suzuki phase and with Mn2+-cation vacancy dipoles. The peak positions of these Mn2+-crystal-field-sensitive transitions were fitted theoretically with expressions including Racah-Tress and seniority corrections. This procedure allowed the determination of the relevant crystal-field parameters.

  3. Proteome Analyses of Staphylococcus aureus Biofilm at Elevated Levels of NaCl

    PubMed Central

    Islam, Nazrul; Ross, Julia M; Marten, Mark R

    2016-01-01

    Our studies demonstrate that sodium chloride (NaCl) induces changes in biofilm, mediated by increased production of polysaccharides intercellular adhesion (PIA). We identified 12 proteins that showed higher abundance in increased level of NaCl. This includes one important protein (IsaA) known to be associated with biofilm stability. In addition, we also found higher abundance of a cold shock protein, CspA, at higher NaCl. We have also identified several other proteins that are differentially expressed to the elevated levels of NaCl and mapped them in the regulatory pathways of PIA. The majority of proteins are involved with various aspects bacterial metabolic function. Our results demonstrated that NaCl influences gene regulatory networks controlling exopolysaccharide expression. PMID:26973848

  4. Concentration and precipitation of NaCl and KCl from salt cake leach solutions by electrodialysis

    SciTech Connect

    Sreenivasarao, K; Patsiogiannis, F.; Hryn, J.N.

    1997-02-09

    Electrodialysis was investigated for cost-effective recovery of salt from salt cake leach solutions. (Salt cake is a waste stream generated by the aluminum industry during treatment of aluminum drosses and scrap.) We used a pilot-scale electrodialysis stack of 5 membrane pairs, each with an effective area of 0.02 m{sup 2}. The diluate stream contained synthetic NaCl, KCl,mixtures of NaCl and KCl, and actual salt cake leach solutions (mainly NaCl and KCl, with small amounts of MgCl{sub 2}). We concentrated and precipitated NaCl and KCl salts from the concentrate steam when the initial diluate stream concentration was 21.5 to 28.8 wt% NaCl and KCl. We found that water transferring through the membranes was a significant factor in overall efficiency of salt recovery by electrodialysis.

  5. Ellipsometric study of cubic SiC

    NASA Technical Reports Server (NTRS)

    Alterovitz, Samuel A.; Shoemaker, Neil S.; Powell, J. A.

    1990-01-01

    Variable angle spectroscopic ellipsometry (VASE) was applied to cubic SiC. This technique gives absolute values of the refractive index (n) and the extinction coefficient (k) of a substrate and/or a thin film of unknown material. The samples were grown by chemical vapor deposition (CVD) on p-type silicon. The substrate was aligned either on the (001) axis or 1 degree of (001). Several growth temperatures and growth durations were used. The samples were divided into two groups: (1) thick films of order 10 microns grown near optimal conditions of temperature, flow, and gas ratio; and (2) thin films of order 100 A grown at various temperatures. The ellipsometric results for samples in group 1 were analyzed using a two-phase model (substrate and ambient). Results show that for wavelengths in the visible, the refractive index of these CVD samples is equal to that reported for single crystal cubic SiC, within the experimental error, which is on the order of 1 percent. However, the extinction coefficient has a relatively large value, even above the band gap. The absorption is sample dependent and has a broad peak in the visible. The results for samples in group 2 were analyzed using a three-phase model (substrate, film, and ambient). The dielectric functions of the film, deducted from the measured n and k, were further analyzed using the effective medium approximation. The results show that the films contain 30 to 40 vol. percent amorphous silicon, i.e., silicon with only short-range order.

  6. Physiological effects of NaCl on Apocynum venetum seedlings

    NASA Astrophysics Data System (ADS)

    Han, Wei; Cao, Ling

    2016-04-01

    The physiological effects of NaCl on the Apocynum venetum seedlings were investigated, including the chlorophyll a fluorescence, leaf potential and growth rate, etc. The findings indicated that along with hardness index increasing, the leaf sample's chlorophyll content assumed the fluctuation condition which dropped firstly elevated again; the leaf water potential maintained stable basically; the energy of light absorption, the assignment and the dissipation balanced at 10 g/L and the growth rate presented the maximum value 9.8 mm/d; Along with the stress extension, the greatest quantum yield Fv/Fm dropped, metallic ion's absorption increased. In the 21st day, non-photochemical quenching coefficient NPQ presented the maximum value, absorbed energy proportion parameter Y(II) dropped firstly restored again, 3 kind of energy absorptions, the assignment dissipation parameter proportion stabilized in 10 g/L at Y(II):Y(NO):Y(NPQ) = 65%:20%:15%.The results suggested that in the A. venetum nursery process in the southern edge of Taklimakan Desert, phased tending should be adopted according to the seedling stage: 5-10 g/L salinity water should be used in irrigation in the seedling stage to maintain a more high leaf water potential which could prevent the decomposition of chlorophyll in which higher proportion of photochemical energy conversion could be stable using 10 g/L salt water irrigation to give A. venetum a full play of stronger salt adaptability to the southern margin of the Taklimakan Desert Oasis-Desert Ecotone in its restoration and construction. Key words: saline water irrigation; leaf water potential; energy allocation strategies; growth rate

  7. An unconventional bilayer ice structure on a NaCl(001) film

    NASA Astrophysics Data System (ADS)

    Chen, Ji; Guo, Jing; Meng, Xiangzhi; Peng, Jinbo; Sheng, Jiming; Xu, Limei; Jiang, Ying; Li, Xin-Zheng; Wang, En-Ge

    2014-05-01

    Water-solid interactions are of broad importance both in nature and technology. The hexagonal bilayer model based on the Bernal-Fowler-Pauling ice rules has been widely adopted to describe water structuring at interfaces. Using a cryogenic scanning tunnelling microscope, here we report a new type of two-dimensional ice-like bilayer structure built from cyclic water tetramers on an insulating NaCl(001) film, which is completely beyond this conventional bilayer picture. A novel bridging mechanism allows the interconnection of water tetramers to form chains, flakes and eventually a two-dimensional extended ice bilayer containing a regular array of Bjerrum D-type defects. Ab initio density functional theory calculations substantiate this bridging growth mode and reveal a striking proton-disordered ice structure. The formation of the periodic Bjerrum defects with unusually high density may have a crucial role as H donor sites in directing multilayer ice growth and in catalysing heterogeneous chemical reactions on water-coated salt surfaces.

  8. Orientation dependence of the dislocation microstructure in compressed body-centered cubic molybdenum

    SciTech Connect

    Wang, S.; Wang, M.P.; Chen, C.; Xiao, Z.; Jia, Y.L.; Li, Z.; Wang, Z.X.

    2014-05-01

    The orientation dependence of the deformation microstructure has been investigated in commercial pure molybdenum. After deformation, the dislocation boundaries of compressed molybdenum can be classified, similar to that in face-centered cubic metals, into three types: dislocation cells (Type 2), and extended planar boundaries parallel to (Type 1) or not parallel to (Type 3) a (110) trace. However, it shows a reciprocal relationship between face-centered cubic metals and body-centered cubic metals on the orientation dependence of the deformation microstructure. The higher the strain, the finer the microstructure is and the smaller the inclination angle between extended planar boundaries and the compression axis is. - Highlights: • A reciprocal relationship between FCC metals and BCC metals is confirmed. • The dislocation boundaries can be classified into three types in compressed Mo. • The dislocation characteristic of different dislocation boundaries is different.

  9. Interionic hydration structures of NaCl in aqueous solution: a combined study of quantum mechanical cluster calculations and QM/EFP-MD simulations.

    PubMed

    Ghosh, Manik K; Re, Suyong; Feig, Michael; Sugita, Yuji; Choi, Cheol Ho

    2013-01-10

    The association process of NaCl in aqueous solution was studied by a combination of quantum mechanical calculations on NaCl(H(2)O)(n) (n = 1-6) clusters and quantum mechanical/effective fragment potential-molecular dynamics (QM/EFP-MD) simulations for NaCl in 292 EFP waters. The interionic hydration structures (IHSs) were topologically classified as "ring" (R), "half-bridge" (H), and "full-bridge" (F) types on the basis of the quantum mechanical calculations. Subsequent IHS analysis on QM/EFP-MD simulations revealed that the NaCl contact ion pair (CIP) mainly involved R type hydration structures while the solvent-separated ion pair (SSIP) was composed of two different groups of F-type hydration structures. Our IHS analysis also discovered H type hydration even at large separation interionic distances (∼7 Å), which is denoted as a dissociating ion pair (DIP). The analysis was able to reveal the most complete interionic structures and their reorganizations of the association process. A strong correlation between the IHSs and interionic distance suggests that not only the solvent reorganization but also the local IHS changes are equally important. Mechanistically, it is suggested that the conversion between ring-type and full-bridge hydration structures is the main rate-determining step of ion-pair association. PMID:23231378

  10. Pre- and initial stages of epitaxy in alkali halide systems. II. Interaction of molecular beams of CsCl with (100) surfaces of NaCl

    NASA Astrophysics Data System (ADS)

    Dabringhaus, H.; Haag, M.

    The interaction of molecular beams of CsCl with (100) surfaces of NaCl is studied for crystal temperatures between 560 and 620 K and for molecular beam fluxes between 2 × 10 7 and 2 × 10 13 cm -2 s -1 by measurements of transient and steady state desorption fluxes, by static SIMS, and by electron microscopy. Also for the large Cs + ions a fast cation exchange Cs + ⇌ Na + between CsCl molecules adsorbed on the terrace and the outermost surface layer of the NaCl crystal is observed. The results for undersaturation are interpreted by incorporation of Cs + ions in the outermost surface layer of the NaCl crystal and by adsorption of CsCl molecules at the monatomic steps on the surface. The outermost surface layer proves to have a maximum capacity for Cs + of 2.4 × 10 11 cm -2. The residence time of Cs + ions in the outermost surface layer is determined as τ0 = 1.6 × 10 -12 exp(1.49 (eV)/ kT), the time for desorption of CsCl molecules from the monatomic steps as τ1 = 2.9 × 10 -14 exp(1.60 (eV)/ kT). By experiments with an additional NaCl flux onto the surface it is shown that τ0 is the time for a back-exchange of Cs + ions from the outermost surface layer against Na + from NaCl admolecules. For supersaturation the growth of polymorphic CsCl islands is observed. In the first growth stages these islands show the NaCl-type structure, while for later growth stages the CsCl type structure is found. A comparative discussion of all studied alkali halide systems shows that the different results can be attributed to the different radii of guest and host cation and to lattice misfits, respectively.

  11. Using ultra-weak luminescence to evaluate NaCl stress resistance of maize varieties

    NASA Astrophysics Data System (ADS)

    Chi, Guirong

    2009-08-01

    In this paper, the delayed ultra-weak luminescence (UWL), Nitrate reductase (NR) activity, and reactive oxygen species (ROS) contents of maize varieties (Zhengdan958 and Jundan20) under 100 and 200 mmol NaCl stress were analyzed. The results showed that the UWL intensity was decreased and the curve attenuating accelerated under the NaCl stress. With the NaCl concentration increasing, the total photon number reduced more notably, compared with Jundan20, the decreasing of total photon number and the tendency of curve attenuating was more obviously. The activity of Nitrate reductase, which is a key marker reflecting internal physiology status, decrease 18% in Zhengdan958 and 15.4% in Jundan20 under 100 mmol NaCl, while it decreased 28.8% and 31.07 under 200 mmol NaCl, respectively. Contrarily, the ROS contents increased remarkably, ranging from 146% to 116% under different NaCl stress in Zhengdan958 and Jundan20, respectively, the corresponding value at 200 mmol NaCl were increased from 525% to 543%, respectively. Summarized, the NaCl resistance of Jundan20 was superior to Zhengdan958. From these results, it was suggested that UWL decreasing tendency was consisting with the change character of Nitrate reductase activity, and rather the in vivo metabolism reactions than the ROS contents, was the main resources of ultraweak photon emitting. In conclusion, the UWL and the physiological status are closely related, ultra-weak luminescence could be used as a time-saving, sensitive method for evaluating NaCl stress resistance of different maize varieties.

  12. Supersymmetric cubic Galileons have ghosts

    NASA Astrophysics Data System (ADS)

    Koehn, Michael; Lehners, Jean-Luc; Ovrut, Burt A.

    2013-07-01

    Galileons are higher-derivative theories of a real scalar which nevertheless admit second-order equations of motion. They have interesting applications as dark energy models and in early universe cosmology, and have been conjectured to arise as descriptions of brane dynamics in string theory. In the present paper, we study the bosonic sector of globally N=1 supersymmetric extensions of the cubic Galileon Lagrangian in detail. Supersymmetry requires that the Galileon scalar now becomes paired with a second real scalar field. We prove that the presence of this second scalar causes the equations of motion to become higher than second order, thus leading to the appearance of ghosts. We also analyze the energy scales up to which, in an effective field theory description, the ghosts can be tamed.

  13. Evidence for an apical Na-Cl cotransporter involved in ion uptake in a teleost fish

    USGS Publications Warehouse

    Hiroi, J.; Yasumasu, S.; McCormick, S.D.; Hwang, P.-P.; Kaneko, T.

    2008-01-01

    Cation-chloride cotransporters, such as the Na+/K +/2Cl- cotransporter (NKCC) and Na+/Cl - cotransporter (NCC), are localized to the apical or basolateral plasma membranes of epithelial cells and are involved in active ion absorption or secretion. The objectives of this study were to clone and identify 'freshwater-type' and 'seawater-type' cation-chloride cotransporters of euryhaline Mozambique tilapia (Oreochromis mossambicus) and to determine their intracellular localization patterns within mitochondria-rich cells (MRCs). From tilapia gills, we cloned four full-length cDNAs homologous to human cation-chloride cotransporters and designated them as tilapia NKCC1a, NKCC1b, NKCC2 and NCC. Out of the four candidates, the mRNA encoding NKCC1a was highly expressed in the yolk-sac membrane and gills (sites of the MRC localization) of seawater-acclimatized fish, whereas the mRNA encoding NCC was exclusively expressed in the yolk-sac membrane and gills of freshwater-acclimatized fish. We then generated antibodies specific for tilapia NKCC1a and NCC and conducted whole-mount immunofluorescence staining for NKCC1a and NCC, together with Na+/K+-ATPase, cystic fibrosis transmembrane conductance regulator (CFTR) and Na+/H+ exchanger 3 (NHE3), on the yolk-sac membrane of tilapia embryos acclimatized to freshwater or seawater. The simultaneous quintuple-color immunofluorescence staining allowed us to classify MRCs clearly into four types: types I, II, III and IV. The NKCC1a immunoreactivity was localized to the basolateral membrane of seawater-specific type-IV MRCs, whereas the NCC immunoreactivity was restricted to the apical membrane of freshwater-specific type-II MRCs. Taking account of these data at the level of both mRNA and protein, we deduce that NKCC1a is the seawater-type cotransporter involved in ion secretion by type-IV MRCs and that NCC is the freshwater-type cotransporter involved in ion absorption by type-II MRCs. We propose a novel ion-uptake model by MRCs in

  14. Evidence for an apical Na-Cl cotransporter involved in ion uptake in a teleost fish.

    PubMed

    Hiroi, Junya; Yasumasu, Shigeki; McCormick, Stephen D; Hwang, Pung-Pung; Kaneko, Toyoji

    2008-08-01

    Cation-chloride cotransporters, such as the Na(+)/K(+)/2Cl(-) cotransporter (NKCC) and Na(+)/Cl(-) cotransporter (NCC), are localized to the apical or basolateral plasma membranes of epithelial cells and are involved in active ion absorption or secretion. The objectives of this study were to clone and identify ;freshwater-type' and ;seawater-type' cation-chloride cotransporters of euryhaline Mozambique tilapia (Oreochromis mossambicus) and to determine their intracellular localization patterns within mitochondria-rich cells (MRCs). From tilapia gills, we cloned four full-length cDNAs homologous to human cation-chloride cotransporters and designated them as tilapia NKCC1a, NKCC1b, NKCC2 and NCC. Out of the four candidates, the mRNA encoding NKCC1a was highly expressed in the yolk-sac membrane and gills (sites of the MRC localization) of seawater-acclimatized fish, whereas the mRNA encoding NCC was exclusively expressed in the yolk-sac membrane and gills of freshwater-acclimatized fish. We then generated antibodies specific for tilapia NKCC1a and NCC and conducted whole-mount immunofluorescence staining for NKCC1a and NCC, together with Na(+)/K(+)-ATPase, cystic fibrosis transmembrane conductance regulator (CFTR) and Na(+)/H(+) exchanger 3 (NHE3), on the yolk-sac membrane of tilapia embryos acclimatized to freshwater or seawater. The simultaneous quintuple-color immunofluorescence staining allowed us to classify MRCs clearly into four types: types I, II, III and IV. The NKCC1a immunoreactivity was localized to the basolateral membrane of seawater-specific type-IV MRCs, whereas the NCC immunoreactivity was restricted to the apical membrane of freshwater-specific type-II MRCs. Taking account of these data at the level of both mRNA and protein, we deduce that NKCC1a is the seawater-type cotransporter involved in ion secretion by type-IV MRCs and that NCC is the freshwater-type cotransporter involved in ion absorption by type-II MRCs. We propose a novel ion-uptake model

  15. First-principles study of dielectric properties of bulk NaCl and ultrathin NaCl films under a finite external electric field

    NASA Astrophysics Data System (ADS)

    Ono, Tomoya; Hirose, Kikuji

    2005-08-01

    We present a first-principles study of the dielectric properties of a NaCl crystal and ultrathin NaCl films under a finite external electric field. Our results show that the high-frequency dielectric constant of the films is less affected by the finite-size effect from crystal surfaces and is close to that of the crystal, whereas the static one is sensitive to the thickness of the film because of the thick buffer region where ionic displacements due to the electric field are not as homogeneous as those in the bulk.

  16. How NaCl and water content determine water activity during ripening of Gouda cheese, and the predicted effect on inhibition of Listeria monocytogenes.

    PubMed

    Wemmenhove, E; Wells-Bennik, M H J; Stara, A; van Hooijdonk, A C M; Zwietering, M H

    2016-07-01

    This study describes the diffusion of NaCl and water in Gouda cheese during brining and ripening. Furthermore, we established water activity as a function of the NaCl-in-moisture content in Gouda cheese during ripening. We determined NaCl content, water content, and water activity in block-type Gouda cheeses that were brined for 3.8d and foil-ripened for a period of 26 wk, and in wheel-type Gouda cheeses that were brined for 0.33, 2.1, or 8.9d and subsequently nature-ripened for a period of 26 wk. The calculated diffusion coefficients of NaCl during brining were 3.6·10(-10) m(2)s(-1) in the block-type Gouda cheeses and 3.5·10(-10) m(2)s(-1) in the wheel-type Gouda cheeses. Immediately after brining, gradients of NaCl and water were observed throughout both types of cheese. During ripening, these gradients disappeared, except for the water gradient in nature-ripened cheeses. An empirical model was derived for Gouda cheese, in which water activity is expressed as a function of the NaCl-in-moisture content, as established for different brining times, locations and ripening times. Moreover, the effect of reduced water activity on inhibition of growth of Listeria monocytogenes in Gouda cheese was calculated. In addition to the presence of lactate and a pH of 5.2 to 5.3, the reduced water activity as seen in Gouda cheese can substantially contribute to inhibition of microbial growth and even to inactivation when cheeses are brined and ripened for extended times and subjected to nature-ripening. PMID:27085417

  17. Growth of NaCl on thin epitaxial KCl films on Ag(100) studied by SPA-LEED

    NASA Astrophysics Data System (ADS)

    Marquardt, Christian; Paulheim, Alexander; Sokolowski, Moritz

    2015-11-01

    We investigated the growth of NaCl on thin (100)-oriented films of KCl by spot profile analysis of low energy electron diffraction (SPA-LEED). The underlying question of this investigation was how the system accommodates to the misfit of - 10% between the NaCl and KCl lattices. The KCl films (3 atomic layers thick) were epitaxially grown on a Ag(100) single crystal. We studied the heteroepitaxial growth of NaCl on KCl at 300 K and at 500 K, respectively. At 300 K, the first NaCl monolayer (ML) grows pseudomorphically on the KCl film. From the second layer onward, the NaCl lattice relaxes. The NaCl multilayers roughen, and a small rotational disorder (± 4°) of the NaCl domains is observed. The roughening results from the formation of multilayer islands of limited lateral size due to the misfit to the pseudomorphic first NaCl layer. At a growth temperature of 500 K, no pseudomorphic NaCl layer forms, instead relaxed multilayer island growth of NaCl is observed from the first layer onward. Similarly to the growth at 300 K, we find NaCl multilayer islands of limited lateral size. For both temperatures, we explain this growth behavior by the misfit that makes the adsorption sites at the island edges of the first relaxed NaCl layer less favorable for larger islands, promoting nucleation of multilayer islands.

  18. "JCE" Classroom Activity Connections: NaCl or CaCl[subscript 2], Smart Polymer Gel Tells More

    ERIC Educational Resources Information Center

    Chen, Yueh-Huey; Lin, Jia-Ying; Wang, Yu-Chen; Yaung, Jing-Fun

    2010-01-01

    This classroom activity connection demonstrates the differences between the effects of NaCl (a salt of monovalent metal ions) and CaCl[subscript 2] (a salt of polyvalent metal ions) on swollen superabsorbent polymer gels. Being ionic compounds, NaCl and CaCl[subscript 2] both collapse the swollen polymer gels. The gel contracted by NaCl reswells…

  19. Experimental determination of the H2O + 15 wt% NaCl and H2O + 25 wt% NaCl liquidi to 1.4 GPa

    NASA Astrophysics Data System (ADS)

    Valenti, P.; Schmidt, C.

    2009-12-01

    The binary H2O+NaCl is one of the most important model systems for chloridic fluids in many geologic environments such as the Earth’s crust, upper mantle, and subducting slabs, and is also applicable to extraterrestrial icy planetary bodies (e.g., Manning 2004, Zolensky et al., 1999). The knowledge on phase equilibria and PVTx properties of this system is still fragmentary at high pressures, e.g., very little has been reported on liquidi at compositions <30 wt% NaCl (Manning and Daniel 2008). In this study, we investigated the liquidus of 15 and 25 wt% NaCl solutions at pressures up to 1.4 GPa. The experiments were performed using a hydrothermal diamond-anvil cell (Bassett et al. 1993) modified for Raman spectroscopy and accurate temperature measurements. A quartz chip, halite, and water were loaded into the sample chamber, which also contained a small trapped air bubble (10 vol%) when it was sealed. The actual salinity was then determined from measurement of the vapor-saturated liquidus temperature. The sample chamber was then compressed until the bubble disappeared. After freezing, phase transitions occurring with increasing temperature were observed optically, and the pressure was determined from the frequency shift of the 464 cm-1 Raman line of quartz (Schmidt and Ziemann 2000). The sample chamber was then compressed further, and the experiment was repeated at various bulk densities until a pressure of ~1.4 GPa was attained. At some conditions, Raman spectra were acquired for identification of the phase assemblage. The solution always crystallized to a single phase upon cooling above ~0.15 GPa at 25 wt% NaCl and above ~1 GPa at 15 wt% NaCl. Raman spectra in the OH stretching region indicate that this phase contains or is a NaCl hydrate other than hydrohalite, probably in solid solution with ice. Melting of this phase produced liquid and hydrohalite and/or ice VI. Ice VI was the last solid that dissolved upon heating, between 1100 MPa, 3 °C and 1370 MPa, 17

  20. Positron beam investigations of natural cubic and coated diamonds

    NASA Astrophysics Data System (ADS)

    Shiryaev, A. A.; van Veen, A.; Schut, H.; Kruseman, A. C.; Zakharchenko, O. D.

    2000-06-01

    Positron beam and 2D-ACAR investigation of cubic and coated diamonds are reported. In type IIA diamonds, positrons are mostly trapped in vacancies in the carbon lattice; in type Ia diamonds, two main defect-related annihilation sites are nitrogen-vacancy complexes (H2, H3) and the vicinity of split interstitial atoms. No correlation between principal nitrogen defects and annihilation rate was found. PAS data indicate the presence of a significant amount of vacancies in all studied diamonds, which increases the rate of nitrogen aggregation. It is shown that pressurised fluid inclusions may serve as a positron trap, giving rise to the long component in the lifetime spectra.

  1. Optimization, characterization and evaluation of chitosan-tailored cubic nanoparticles of clotrimazole.

    PubMed

    Verma, Purnima; Ahuja, Munish

    2015-02-01

    The present study deals with improvement of the mucoadhesive properties of monoolein based cubic nanoparticles by incorporating chitosan. Chitosan-tailored cubic nanoparticles were prepared by thin film hydration followed by ultrasonication employing clotrimazole as model drug. The effect of Pluronic F127 fraction and concentration of chitosan on particle size and % mucin binding of the formulations was studied using 2-factor, 3-level, central composite experimental design. The concentration of chitosan was found to influence particle size and % mucin binding of cubic nanoparticles while Pluronic F127 fraction influenced only the % mucin binding. Studies indicated 8.33(%w/w) fraction of Pluronic F127 and 0.17 (%w/v) concentration of chitosan as optimum concentration. Finally, the optimized batch was characterized by polarized light microscopy, small-angle X-ray scattering (SAXS) and transmission electron microscopy. The results unveiled incorporation of chitosan did not disrupt the inner cubic structure of nanoparticles. Peak indexing of SAXS data revealed the coexistence of P-type and D-type cubic phases in nanoparticles. Further, comparative evaluation studies showed significantly higher anti-fungal activity of clotrimazole-loaded chitosan-tailored cubic nanoparticles than conventional suspension of clotrimazole against Candida albicans. PMID:25463320

  2. Energy flux and osmoregulation of Saccharomyces cerevisiae grown in chemostats under NaCl stress.

    PubMed Central

    Olz, R; Larsson, K; Adler, L; Gustafsson, L

    1993-01-01

    The energetics and accumulation of solutes in Saccharomyces cerevisiae were investigated for cells grown aerobically in a chemostat under NaCl stress and glucose limitation. Changed energy requirements in relation to external salinity were examined by energy balance determinations performed by substrate and product analyses, with the latter including heat measurements by microcalorimetry. In both 0 and 0.9 M NaCl cultures, the catabolism was entirely respiratory at the lowest dilution rates tested but shifted to a mixed respiratory-fermentative metabolism at higher dilution rates. This shift occurred at a considerably lower dilution rate for salt-grown cells. The intracellular solute concentrations, as calculated on the basis of intracellular soluble space determinations, showed that the internal Na+ concentration increased from about 0.02 molal in basal medium to about 0.18 molal in 0.9 M NaCl medium, while intracellular K+ was maintained around 0.29 molal despite the variation in external salinity. The intracellular glycerol concentration increased from below 0.05 molal at low salinity to about 1.2 molal at 0.9 M NaCl. The concentrations of the internal solutes, however, changed insignificantly with growth rate and energy metabolism. The additional maintenance energy expenditure for growth at 0.9 M NaCl was, depending on the growth rate, 14 to 31% of the total energy requirement for growth at 0 M NaCl. Including the energy conserved in glycerol, the total additional energy demand for growth at 0.9 M NaCl corresponded to 28 to 51% of the energy required for growth at 0 M NaCl. Images PMID:8468281

  3. Expression of Virulence-Related Genes in Listeria monocytogenes Grown on Danish Hard Cheese as Affected by NaCl Content.

    PubMed

    Larsen, Nadja; Jespersen, Lene

    2015-06-01

    Expression of virulence-related genes in Listeria monocytogenes incubated on cheese was assessed by real-time quantitative polymerase chain reaction. The objective of the study was to investigate the impact of sodium chloride concentration in cheese on transcription of virulence genes and, thereby, virulence potential of L. monocytogenes. The expression studies were performed with L. monocytogenes strains characterized by different tolerance to salt stress. Strains ATCC(®) 51779 and DSMZ 15675 were incubated on the Danish hard-cheese type Samsoe, with low (<0.15% [wt/wt]) and high (3.6% [wt/wt]) content of NaCl. Genes differentially expressed (p<0.05) through the 48-h incubation were transcriptional regulators prfA and agrA, genes of the main virulence cluster inlA, hly, actA, involved in invasion of the epithelial cells, and genes bsh, opuC, gadC, clpP, and ami, associated with osmotic stress responses in L. monocytogenes. The more sensitive strain ATCC(®) 51779 was most responsive, showing significant upregulation of prfA, actA, hly, and bsh both at low and high NaCl. Strain DSMZ 15675 was less responsive to NaCl stress, showing reduced or consistent gene transcription at all conditions. Decreased transcription of agrA, ami, gadC, and opuC in both strains was promoted by low NaCl content. The study indicated that virulence gene expression of L. monocytogenes grown in cheese was affected by NaCl content and that effect was more significant in strains sensitive to both hypo- and hyperosmotic stresses. PMID:26067229

  4. Generalized Vaidya spacetime for cubic gravity

    NASA Astrophysics Data System (ADS)

    Ruan, Shan-Ming

    2016-03-01

    We present a kind of generalized Vaidya solution of a new cubic gravity in five dimensions whose field equations in spherically symmetric spacetime are always second order like the Lovelock gravity. We also study the thermodynamics of its spherically symmetric apparent horizon and get its entropy expression and generalized Misner-Sharp energy. Finally, we present the first law and second law hold in this gravity. Although all the results are analogous to those in Lovelock gravity, we in fact introduce the contribution of a new cubic term in five dimensions where the cubic Lovelock term is just zero.

  5. Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes

    PubMed Central

    Bo, Zheng; Yang, Huachao; Zhang, Shuo; Yang, Jinyuan; Yan, Jianhua; Cen, Kefa

    2015-01-01

    Vertically-oriented graphenes (VGs) are promising active materials for electric double layer capacitors (EDLCs) due to their unique morphological and structural features. This study, for the first time, reports the molecular dynamics (MD) simulations on aqueous NaCl electrolytes confined within VG channels with different surface charge densities and channel widths. Simulation results show that the accessibility of ions and the structure of EDLCs are determined by the ion type/size, surface charging, and VG channel width. For relatively narrow VG channels with the same width, the threshold charge density (to compensate the energy penalty for shedding hydration shell) and the dehydration rate of Cl− ions are larger than those of Na+ ions. To achieve the highest ion concentration coefficient, the effective VG channel width should be between the crystal and hydration diameters of the ions. The results are further quantified and elucidated by calculating the electrolyte density profiles. The molecular insights obtained in the current work are useful in guiding the design and fabrication of VGs for advancing their EDLC applications. PMID:26424365

  6. Ab initio molecular dynamics study of an aqueous NaCl solution under an electric field.

    PubMed

    Cassone, Giuseppe; Creazzo, Fabrizio; Giaquinta, Paolo V; Saija, Franz; Marco Saitta, A

    2016-08-17

    We report on an ab initio molecular dynamics study of an aqueous NaCl solution under the effect of static electric fields. We found that at low-to-moderate field intensity regimes chlorine ions have a greater mobility than sodium ions which, being a sort of "structure makers", are able to drag their own coordination shells. However, for field strengths exceeding 0.15 V Å(-1) the mobility of sodium ions overcomes that of chlorine ions as both types of ions do actually escape from their respective hydration cages. The presence of charged particles lowers the water dissociation threshold (i.e., the minimum field strength which induces a transfer of protons) from 0.35 V Å(-1) to 0.25 V Å(-1); moreover, a protonic current was also recorded at the estimated dissociation threshold of the solution. The behaviour of the current-voltage diagram of the protonic response to the external electric field is Ohmic as in pure water, with a resulting protonic conductivity of about 2.5 S cm(-1). This value is approximately one third of that estimated in pure water (7.8 S cm(-1)), which shows that the partial breaking of hydrogen bonds induced by the solvated ions hinders the migration of protonic defects. Finally, the conductivity of Na(+) and Cl(-) ions (0.2 S cm(-1)) is in fair agreement with the available experimental data for a solution molarity of 1.7 M. PMID:27494789

  7. Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes.

    PubMed

    Bo, Zheng; Yang, Huachao; Zhang, Shuo; Yang, Jinyuan; Yan, Jianhua; Cen, Kefa

    2015-01-01

    Vertically-oriented graphenes (VGs) are promising active materials for electric double layer capacitors (EDLCs) due to their unique morphological and structural features. This study, for the first time, reports the molecular dynamics (MD) simulations on aqueous NaCl electrolytes confined within VG channels with different surface charge densities and channel widths. Simulation results show that the accessibility of ions and the structure of EDLCs are determined by the ion type/size, surface charging, and VG channel width. For relatively narrow VG channels with the same width, the threshold charge density (to compensate the energy penalty for shedding hydration shell) and the dehydration rate of Cl(-) ions are larger than those of Na(+) ions. To achieve the highest ion concentration coefficient, the effective VG channel width should be between the crystal and hydration diameters of the ions. The results are further quantified and elucidated by calculating the electrolyte density profiles. The molecular insights obtained in the current work are useful in guiding the design and fabrication of VGs for advancing their EDLC applications. PMID:26424365

  8. New tetragonal derivatives of cubic NaZn13-type structure: RNi6Si6 compounds, crystal structure and magnetic ordering (R=Y, La, Ce, Sm, Gd-Yb)

    NASA Astrophysics Data System (ADS)

    Pani, M.; Manfrinetti, P.; Provino, A.; Yuan, Fang; Mozharivskyj, Y.; Morozkin, A. V.; Knotko, A. V.; Garshev, A. V.; Yapaskurt, V. O.; Isnard, O.

    2014-02-01

    Novel RNi6Si6 compounds adopt the new CeNi6Si6-type structure for R=La-Ce (tP52, space group P4/nbm N 125-1) and new YNi6Si6-type structure for R=Y, Sm, Gd-Yb (tP52, space group P4barb2N 117) that are tetragonal derivative of NaZn13-type structure, like LaCo9Si4-type. The CeNi6Si6, GdNi6Si6, TbNi6Si6, DyNi6Si6 and HoNi6Si6 compounds are Curie-Weiss paramagnets down to ~30 K, and do not order magnetically down to 5 K. However, the inverse paramagnetic susceptibility of LaNi6Si6 does not follow Curie-Weiss law. The DyNi6Si6 shows ferromagnetic-like saturation behaviour at 5 K in applied fields of 50 kOe, giving rise to a magnetic moment value of 6.5 μB/f.u. in 50 kOe. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi6Si6 with K=[±1/4, ±1/4, 0] wave vector below ~10 K. The CeNi6Si6, GdNi6Si6, TbNi6Si6, DyNi6Si6 and HoNi6Si6 compounds are Curie-Weiss paramagnets down to ~30 K, and do not order magnetically down to 4.2 K. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi6Si6 with K=[±1/4, ±1/4, 0] wave vector below ~10 K.

  9. Radiation damage in cubic-stabilized zirconia

    SciTech Connect

    Costantini, Jean-Marc; Beuneu, Francois; Weber, William J

    2013-01-01

    Cubic yttria-stabilized zirconia (YSZ) can be used for nuclear applications as an inert matrix for actinide immobilization or transmutation. Indeed, the large amount of native oxygen vacancies leads to a high radiation tolerance of this material owing to defect recombination occurring in the atomic displacements cascades induced by fast neutron irradiation or ion implantations, as showed by Molecular dynamics (MD) simulations. Amorphization cannot be obtained in YSZ either by nuclear-collision or electronic-excitation damage, just like in urania. A kind of polygonization structure with slightly disoriented crystalline domains is obtained in both cases. In the first steps of damage, specific isolated point defects (like F+-type color centers) and point-defect clusters are produced by nuclear collisions with charged particles or neutrons. Further increase of damage leads to dislocation-loop formation, then to collapse of the dislocation network into a polygonization structure. For swift heavy ion irradiations, a similar polygonization structure is obtained above a threshold stopping power value of about 20-30 keV nm-1.

  10. Smooth cubic commensurate oxides on gallium nitride

    SciTech Connect

    Paisley, Elizabeth A.; Gaddy, Benjamin E.; LeBeau, James M.; Shelton, Christopher T.; Losego, Mark D.; Mita, Seiji; Collazo, Ramón; Sitar, Zlatko; Irving, Douglas L.; Maria, Jon-Paul; Biegalski, Michael D.; Christen, Hans M.

    2014-02-14

    Smooth, commensurate alloys of 〈111〉-oriented Mg{sub 0.52}Ca{sub 0.48}O (MCO) thin films are demonstrated on Ga-polar, c+ [0001]-oriented GaN by surfactant-assisted molecular beam epitaxy and pulsed laser deposition. These are unique examples of coherent cubic oxide|nitride interfaces with structural and morphological perfection. Metal-insulator-semiconductor capacitor structures were fabricated on n-type GaN. A comparison of leakage current density for conventional and surfactant-assisted growth reveals a nearly 100× reduction in leakage current density for the surfactant-assisted samples. HAADF-STEM images of the MCO|GaN interface show commensurate alignment of atomic planes with minimal defects due to lattice mismatch. STEM and DFT calculations show that GaN c/2 steps create incoherent boundaries in MCO over layers which manifest as two in-plane rotations and determine consequently the density of structural defects in otherwise coherent MCO. This new understanding of interfacial steps between HCP and FCC crystals identifies the steps needed to create globally defect-free heterostructures.

  11. Effect of NaCl concentration on productivity and mineral composition of Salicornia europaea as a potential crop for utilization NaCl in LSS

    NASA Astrophysics Data System (ADS)

    Ushakova, S. A.; Kovaleva, N. P.; Gribovskaya, I. V.; Dolgushev, V. A.; Tikhomirova, N. A.

    The accumulation of solid and liquid wastes in manmade ecosystems presents a problem that has not been efficiently solved yet. Urine, containing NaCl, are part of these products. This is an obstacle to the creation of biological systems with a largely closed material cycling, because the amount of solid and liquid wastes in them must be reduced to a minimum. A possible solution to the problem is to select plant species capable of utilizing sufficiently high concentrations of NaCl, edible for humans, and featuring high productivity. Until recently, the life support systems have included the higher plants that were either sensitive to salinization (wheat, many of the legumes, carrot, potato, maize) or relatively salt-resistant (barley, sugar beet, spinach). Salicomia europaea, whose above-ground part is fully edible for humans, is one of the most promising candidates to be included in life support systems. It is reported in the literature that this plant is capable of accumulating up to 50% NaCl (dry basis). Besides, excessive accumulation of sodium ions should bring forth a decrease in the uptake of potassium ions and other biogenic elements. The aim of this work is to study the feasibility of using S. europaea plants in growth chambers to involve NaCl into material cycling. Plants were grown in vegetation chambers at the irradiance of 100 or 150 W/m 2 PAR (photosynthetically active radiation) and the air temperature 24 °C, by two methods. The first method was to grow the plants on substrate - peat. The peat was supplemented with either 3% NaCl (Variant 1) or 6% NaCl (Variant 2) of the oven-dry mass of the peat. The second method was to grow the plants in water culture, using the solution with a full complement of nutrients, which contained 0.0005% of NaCl, 1% or 2%. The study showed that the addition of NaCl to the substrate or to the solution resulted in the formation of more succulent plants, which considerably increased their biomass. The amount of NaCl uptake

  12. Hygroscopic properties of internally mixed particles composed of NaCl and water-soluble organic acids.

    PubMed

    Ghorai, Suman; Wang, Bingbing; Tivanski, Alexei; Laskin, Alexander

    2014-02-18

    Atmospheric aging of naturally emitted marine aerosol often leads to formation of internally mixed particles composed of sea salts and water-soluble organic compounds of anthropogenic origin. Mixing of sea salt and organic components has profound effects on the evolving chemical composition and hygroscopic properties of the resulted particles, which are poorly understood. Here, we have studied chemical composition and hygroscopic properties of laboratory generated NaCl particles mixed with malonic acid (MA) and glutaric acid (GA) at different molar ratios using micro-FTIR spectroscopy, atomic force microscopy, and X-ray elemental microanalysis. Hygroscopic properties of internally mixed NaCl and organic acid particles were distinctly different from pure components and varied significantly with the type and amount of organic compound present. Experimental results were in a good agreement with the AIM modeling calculations of gas/liquid/solid partitioning in studied systems. X-ray elemental microanalysis of particles showed that Cl/Na ratio decreased with increasing organic acid component in the particles with MA yielding lower ratios relative to GA. We attribute the depletion of chloride to the formation of sodium malonate and sodium glutarate salts resulted by HCl evaporation from dehydrating particles. PMID:24437520

  13. Stable isotope labelling reveals that NaCl stress decreases the production of Ensifer (Sinorhizobium) arboris lipochitooligosaccharide signalling molecules.

    PubMed

    Penttinen, Petri; Räsänen, Leena A; Lortet, Gilles; Lindström, Kristina

    2013-12-01

    Ensifer (Sinorhizobium) arboris is a symbiont of salt-tolerant leguminous trees in the genera Acacia and Prosopis that are utilized in the prevention of soil erosion and desertification and in phytoremediation of salinized soil. Signalling between the plant and the rhizobia is essential for the formation of effective symbiosis that increases the success of reclaiming saline sites. We assessed the effect of salt stress on the growth and the production of lipochitooligosaccharide signalling molecules (LCOs) of S. arboris HAMBI 2361, an LCO-overproducing derivative of the S. arboris type strain HAMBI 1552. The strain tolerated NaCl up to 750 mM. To obtain both qualitative and quantitative information on the LCO production under salt stress, we devised a method where LCOs were differentially labelled by stable isotopes of nitrogen, (14)N and (15)N, and analysed by mass spectrometry. Under control conditions, the strain produced altogether 27 structural LCO variants. In 380 mM NaCl, 13 LCO variants were produced in detectable amounts, and six of these were reliably quantified, ranging from one-tenth to one-third of the non-stressed one. PMID:24256411

  14. Hygroscopic Properties of Internally Mixed Particles Composed of NaCl and Water-Soluble Organic Acids

    SciTech Connect

    Ghorai, Suman; Wang, Bingbing; Tivanski, Alexei V.; Laskin, Alexander

    2014-02-18

    Atmospheric aging of naturally emitted marine aerosol often leads to formation of internally mixed particles composed of sea salts and water soluble organic compounds of anthropogenic origin. Mixing of sea salt and organic components has profound effects on the evolving chemical composition and hygroscopic properties of the resulted particles, which are poorly understood. Here, we have studied chemical composition and hygroscopic properties of laboratory generated NaCl particles mixed with malonic acid (MA) and glutaric acid (GA) at different molar ratios using micro-FTIR spectroscopy and X-ray elemental microanalysis.Hygroscopic properties of inte rnally mixed NaCl and organic acid particles were distinctly different from pure components and varied significantly with the type and amount of organic compound present. Experimental results were in a good agreement with the AIM modeling calculations of gas/liquid/solid partitioning in studied systems. X-ray elemental microanalysis of particles showed that Cl/Na ratio decreased with increasing organic acid component in the particles with MA yielding lower ratios relative to GA. We attribute the depletion of chloride to the formation of Na-malonate and Na-glutarate salts resulted by HCl evaporation from dehydrating particles.

  15. Electrostatic swelling of bicontinuous cubic lipid phases.

    PubMed

    Tyler, Arwen I I; Barriga, Hanna M G; Parsons, Edward S; McCarthy, Nicola L C; Ces, Oscar; Law, Robert V; Seddon, John M; Brooks, Nicholas J

    2015-04-28

    Lipid bicontinuous cubic phases have attracted enormous interest as bio-compatible scaffolds for use in a wide range of applications including membrane protein crystallisation, drug delivery and biosensing. One of the major bottlenecks that has hindered exploitation of these structures is an inability to create targeted highly swollen bicontinuous cubic structures with large and tunable pore sizes. In contrast, cubic structures found in vivo have periodicities approaching the micron scale. We have been able to engineer and control highly swollen bicontinuous cubic phases of spacegroup Im3m containing only lipids by (a) increasing the bilayer stiffness by adding cholesterol and (b) inducing electrostatic repulsion across the water channels by addition of anionic lipids to monoolein. By controlling the composition of the ternary mixtures we have been able to achieve lattice parameters up to 470 Å, which is 5 times that observed in pure monoolein and nearly twice the size of any lipidic cubic phase reported previously. These lattice parameters significantly exceed the predicted maximum swelling for bicontinuous cubic lipid structures, which suggest that thermal fluctuations should destroy such phases for lattice parameters larger than 300 Å. PMID:25790335

  16. A High-Throughput Method to Measure NaCl and Acid Taste Thresholds in Mice

    PubMed Central

    Bachmanov, Alexander A.

    2009-01-01

    To develop a technique suitable for measuring NaCl taste thresholds in genetic studies, we conducted a series of experiments with outbred CD-1 mice using conditioned taste aversion (CTA) and two-bottle preference tests. In Experiment 1, we compared conditioning procedures involving either oral self-administration of LiCl or pairing NaCl intake with LiCl injections and found that thresholds were the lowest after LiCl self-administration. In Experiment 2, we compared different procedures (30-min and 48-h tests) for testing conditioned mice and found that the 48-h test is more sensitive. In Experiment 3, we examined the effects of varying strength of conditioned (NaCl or LiCl taste intensity) and unconditioned (LiCl toxicity) stimuli and concluded that 75–150 mM LiCl or its mixtures with NaCl are the optimal stimuli for conditioning by oral self-administration. In Experiment 4, we examined whether this technique is applicable for measuring taste thresholds for other taste stimuli. Results of these experiments show that conditioning by oral self-administration of LiCl solutions or its mixtures with other taste stimuli followed by 48-h two-bottle tests of concentration series of a conditioned stimulus is an efficient and sensitive method to measure taste thresholds. Thresholds measured with this technique were 2 mM for NaCl and 1 mM for citric acid. This approach is suitable for simultaneous testing of large numbers of animals, which is required for genetic studies. These data demonstrate that mice, like several other species, generalize CTA from LiCl to NaCl, suggesting that they perceive taste of NaCl and LiCl as qualitatively similar, and they also can generalize CTA of a binary mixture of taste stimuli to mixture components. PMID:19188279

  17. Growth and characterization of low yttria-doped fully cubic stabilized zirconia-based single crystals

    NASA Astrophysics Data System (ADS)

    Berendts, Stefan; Lerch, Martin

    2013-05-01

    For the first time, fully cubic stabilized zirconia-based single crystals with large nitrogen contents and optimized anion vacancy concentrations, interesting for new electrochemical devices such as nitrogen sensors, were prepared by a two-step approach. This two-step approach combines growth of nitrogen-free zirconia single crystals via the skull melting method and their subsequent direct nitridation to form cubic nitrogen doped zirconia-based single crystals. In the initial step, zirconia crystals with various yttria contents (2, 3, 4 and 6 mol%) were prepared by the skull-melting technique. As determined by X-ray powder diffraction, tetragonal stabilized crystals were obtained, containing monoclinic segregations, when the yttria content of the grinded crystals was below 4 mol%. Subsequently, the crystals were nitrided with nitrogen gas at 1500 °C using different reaction times. Nitrogen content and crystallographic identity of the nitrided samples were investigated, revealing successful nitrogen incorporation and, hence, full cubic stabilization of the initial nitrogen-free samples also for the lowest yttria content. The degree of deviation from the cubic fluorite-type structure is discussed with respect to crystallographic parameters ('pseudo-cubic factor' etc.). The stabilization of cubic or tetragonal phases to ambient temperature is related to the anion vacancy concentration with respect to different impacts of the anion vacancies generated either by yttria or nitrogen incorporation (effective vacancy concentration [Veff]).

  18. Regulation of Electroneutral NaCl Absorption by the Small Intestine

    PubMed Central

    Kato, Akira; Romero, Michael F.

    2014-01-01

    Na+ and Cl− movement across the intestinal epithelium occurs by several interconnected mechanisms: (1) nutrient coupled Na+ absorption; (2) electroneutral NaCl absorption; (3) electrogenic Cl− secretion by CFTR; and (4) electrogenic Na+ absorption by ENaC. All of these transport modes require a favorable electrochemical gradient maintained by the basolateral Na+-K+-ATPase, a Cl− channel and K+ channels. Electroneutral NaCl absorption is observed from the small intestine to distal colon. This transport is mediated by apical Na+/H+ (NHE2/3) and Cl−/HCO3 − (Slc26a3/a6, others) exchangers that provide the major route of NaCl absorption. Electroneutral NaCl absorption and Cl− secretion by CFTR are oppositely regulated by the autonomic nerve system, immune system, and endocrine system via PKAα, PKCα, cGKII, and/or SGK1. This integrated regulation requires the formation of macromolecular complexes, which mediated by NHERF family of scaffold proteins, and involve internalization of NHE3. Using knockout mice and human mutations, a more detailed understanding of the integrated as well as subtle regulation of electroneutral NaCl absorption by the mammalian intestine has emerged. PMID:21054167

  19. Comparison between NaCl tolerance response and acclimation to cold temperature in Shewanella putrefaciens.

    PubMed

    Leblanc, Laurence; Leboeuf, Céline; Leroi, Françoise; Hartke, Axel; Auffray, Yanick

    2003-03-01

    Two strains of the spoiling bacterium S. putrefaciens showed an adaptation capacity to hyperosmotic shock when they were pretreated with a sublethal concentration of NaCl. The maximal tolerance factor for the CIP 69.29 strain was obtained when cells were incubated for 1 h in the presence of 1.5% NaCl, whereas for the J13.1 strain, an incubation of 15 min in the presence of 1% NaCl seemed to be the optimal conditions to harden the cells against a subsequent lethal salt treatment. During NaCl adaptation and growth at low temperatures (2 degrees C), 37 and 32 polypeptides were induced respectively. Interestingly, 11 proteins were common between the two different stress responses. These proteins and the corresponding genes seem to play a key role in the observed cross-protection towards the NaCl challenge induced by growth of the cultures at 2 degrees C. One of the overlapping proteins has been identified to correspond to the alkyl hydroperoxide reductase (AhpC) of S. putrefaciens. Northern blot analysis showed that induction of this enzyme was accompanied by accumulation of the corresponding transcript under both conditions. PMID:12567236

  20. Proteins associated with adaptation of cultured tobacco cells to NaCl

    SciTech Connect

    Singh, N.K.; Handa, A.K.; Hasegawa, P.M.; Bressan, R.A.

    1985-09-01

    Cultured tobacco cells (Nicotiana tabacum L. cv Wisconsin 38) adapted to grow in medium containing high levels of NaCl or polyethylene glycol (PEG) produce several new or enhanced polypeptide bands on sodium dodecyl sulfate-polyarylamide gel electrophoresis. The intensities of some of the polypeptide bands increase with increasing levels of NaCl adaptation, while the intensities of other polypeptide bands are reduced. Synthesis of 26-kilodalton polypeptide(s) occurs at two different periods during culture growth of NaCl adapted cells. Unadapted cells also incorporate /sup 35/S into a 26-kilodalton polypeptide during the later stage of culture growth beginning at midlog phase. The 26-kilodalton polypeptides from adapted and unadapted cells have similar partial proteolysis peptide maps and are immunologically cross-reactive. During adaptation to NaCl, unadapted cells synthesize and accumulate a major 26-kilodalton polypeptide, and the beginning of synthesis corresponds to the period of osmotic adjustment and culture growth. From their results, the authors suggest an involvement of the 26-kilodalton polypeptide in the adaptation of cultured tobacco cells to NaCl and water stress. 38 references, 11 figures, 2 tables.

  1. Effect of NaCl on the thermal behaviour of wheat starch in excess and limited water.

    PubMed

    Day, Li; Fayet, Claire; Homer, Stephen

    2013-04-15

    The effect of NaCl on the thermal behaviour of wheat starch was investigated with particular focus on starch at low moisture contents (25-45 wt%). Increasing the level of NaCl reduced the starch peak viscosity (in 90% water) as measured by RVA and shifted all of the thermal peaks (up to 120°C) to higher temperatures as observed by DSC. Above a moisture content of 45%, the temperature difference of the first thermal transition of starch in the presence of 2% NaCl and in the absence of NaCl was found to be constant. In the absence of NaCl, the peak temperature of gelatinisation (Tp) increased by 12°C (from 62 to 74°C) as the water content was reduced from 35% to 25%. In the presence of 2% NaCl, the variation in Tp due to changes in water content was significantly reduced. At NaCl concentrations greater than 2% (w/w total), the Tp of the starch remained constant irrespective of water content. Evidence of this effect was observed in situ using confocal microscopy. In the presence of 2% NaCl, images taken at elevated temperatures show little difference in the extent of starch swelling at 25% compared to 45% water content. However, in the absence of NaCl, significantly more swelling was observed at 45% than at 25% water content. With increasing NaCl concentration, the interaction of starch and NaCl became dominate. Thus the on-set of the thermal transitions of starch granules is primarily controlled by the amount of NaCl present, and secondarily by the water content which becomes dominant when the NaCl concentration is low. PMID:23544506

  2. Evidence for a Role of Salicylic Acid in the Oxidative Damage Generated by NaCl and Osmotic Stress in Arabidopsis Seedlings1

    PubMed Central

    Borsani, Omar; Valpuesta, Victoriano; Botella, Miguel A.

    2001-01-01

    Previous studies have shown that salicylic acid (SA) is an essential component of the plant resistance to pathogens. We now show that SA plays a role in the plant response to adverse environmental conditions, such as salt and osmotic stresses. We have studied the responses of wild-type Arabidopsis and an SA-deficient transgenic line expressing a salicylate hydroxylase (NahG) gene to different abiotic stress conditions. Wild-type plants germinated under moderate light conditions in media supplemented with 100 mm NaCl or 270 mm mannitol showed extensive necrosis in the shoot. In contrast, NahG plants germinated under the same conditions remained green and developed true leaves. The lack of necrosis observed in NahG seedlings under the same conditions suggests that SA potentiates the generation of reactive oxygen species in photosynthetic tissues during salt and osmotic stresses. This hypothesis is supported by the following observations. First, the herbicide methyl viologen, a generator of superoxide radical during photosynthesis, produced a necrotic phenotype only in wild-type plants. Second, the presence of reactive oxygen-scavenging compounds in the germination media reversed the wild-type necrotic phenotype seen under salt and osmotic stress. Third, a greater increase in the oxidized state of the glutathione pool under NaCl stress was observed in wild-type seedlings compared with NahG seedlings. Fourth, greater oxidative damage occurred in wild-type seedlings compared with NahG seedlings under NaCl stress as measured by lipid peroxidation. Our data support a model for SA potentiating the stress response of the germinating Arabidopsis seedling. PMID:11457953

  3. Stability and corrosion resistance of superhydrophobic surface on oxidized aluminum in NaCl aqueous solution

    NASA Astrophysics Data System (ADS)

    Lv, Damei; Ou, Junfei; Xue, Mingshan; Wang, Fajun

    2015-04-01

    Superhydrophobic surface (SHS) was fabricated on aluminum via surface roughening by NaClO and surface passivation by hexadecyltrimethoxysilane. The long-term durability for storing the sample in air and the chemical stability for contacting the sample with NaCl solution were investigated. The short-term corrosion resistance for immersing the sample in NaCl solution for 1 h was investigated by potentiodynamic polarization, and the long-term corrosion resistance for immersing the sample in NaCl solution for 7 days was investigated by variation analyses on surface wettability, surface morphology, and surface chemistry. All experimental results suggested that the so-obtained SHS possessed good stability and good corrosion resistance under the testing conditions.

  4. Rats with spontaneous high level of NaCl intake have hypothyroidism.

    PubMed

    Belló, A A; Covian, M R

    1991-11-01

    The thyroid function was studied by means of a comparison between rats that drank daily less than 2 mEq of a NaCl solution (control) and rats that spontaneously drank daily above 4 mEq of this solution (0.25 M), which is considered aversive to rats. It was found that, in these rats, the protein-bound iodine (PBI-127) and the radioactive iodine uptake (I-131) were less than in the control rats, in spite of similar thyroid weight. It seems, therefore, that the rats that drank high levels of the aversive salt solution have hypothyroidism. This finding shows another link between the thyroid gland and NaCl intake. These data have implications in the design and interpretation of experiments in which NaCl intake is studied. PMID:1805272

  5. Heterogeneous nucleation of ice from supercooled NaCl solution confined in porous cement paste

    NASA Astrophysics Data System (ADS)

    Zeng, Qiang; Li, Kefei; Fen-Chong, Teddy

    2015-01-01

    Clarifying the nucleation process of chloride-based deicing salt solution (e.g., NaCl solution) confined in cement-based porous materials remains an important issue to understand its detrimental effects on material substrates. In this study, the pore structures of hardened cement pastes were characterized by mercury-intrusion and nitrogen-sorption porosimetry. The ice nucleation temperature of NaCl solution of different concentrations confined in the hardened cement pastes was measured and analyzed by classical heterogeneous nucleation theory. The kinetic factor, contact-angle factor including the contact angle between ice and the substrate were evaluated. The results revealed that the contact angle between ice and the substrate showed the minimum value when adding 3% NaCl into water. The heterogeneous ice nucleation rates were found to be proportional to the water activity shifts.

  6. Role of titania incorporated on activated carbon cloth for capacitive deionization of NaCl solution.

    PubMed

    Ryoo, Min-Woong; Kim, Jong-Ho; Seo, Gon

    2003-08-15

    Adsorption isotherms of NaCl on activated carbon cloth (ACC) and titania-incorporated activated carbon cloth (Ti-ACC) under an electric field were investigated to deduce the role of titania in capacitive deionization (CDI) of NaCl. Electrosorption of NaCl on the ACC was significantly increased by titania incorporation, whereas its physical adsorption was considerably decreased, resulting in an improved performance of the Ti-ACC as a CDI electrode. Langmuir isotherms based on a localized and fixed amount of adsorption were suitable for the simulation of electrosorption and physical adsorption of ions on the ACC electrodes. The variances of q(m) and b of Langmuir isotherms with electric potential indicate increases in the number of ions per adsorption site and in electrosorption strength of ions by titania incorporation. A cyclic voltammetric study for ion adsorption on ACC electrodes confirms the reversibility between electrosorption and desorption of ions, regardless of titania incorporation. PMID:16256660

  7. Neutralization of Hydroxide Ion in Melt-Grown NaCl Crystals

    NASA Technical Reports Server (NTRS)

    Otterson, Dumas A.

    1961-01-01

    Many recent studies of solid-state phenomena, particularly in the area of crystal imperfections, have involved the use of melt-grown NaCl single crystals. Quite often trace impurities in these materials have had a prominent effect on these phenomena. Trace amounts of hydroxide ion have been found in melt-grown NaCl crystals. This paper describes a nondestructive method of neutralizing the hydroxide ion in such crystals. Crystals of similar hydroxide content are maintained at an elevated temperature below the melting point of NaCl in a flowing atmosphere containing. dry hydrogen chloride. Heat treatment is continued until an analysis of the test specimens shows no excess hydroxide ion. A colorimetric method previously described4 is used for this analysis.

  8. Some aspects of salinity responses in peppermint (Mentha × piperita L.) to NaCl treatment.

    PubMed

    Li, Zhe; Yang, Hetong; Wu, Xiaoqing; Guo, Kai; Li, Jishun

    2015-05-01

    Salinity is a major stress that adversely affects plant growth and crop production. Understanding the cellular responses and molecular mechanisms by which plants perceive and adopt salinity stress is of fundamental importance. In this work, some of the cellular signaling events including cell death, reactive oxygen species (ROS) generation, and the behaviors of organelles were analyzed in a salt-tolerant species (Keyuan-1) of peppermint (Mentha × piperita L.) under NaCl treatment. Our results showed that 200 mM NaCl treatment elicited a distinct progress of cell death with chromatin condensation and caspase-3-like activation and a dramatic burst of ROS which was required for the execution of cell death. The major ROS accumulation occurred in the mitochondria and chloroplasts, which were the sources of ROS production under NaCl stress. Moreover, mitochondrial activity and photosynthetic capacity also exhibited the obvious decrease in the ROS-dependent manner under 200 mM NaCl stress. Furthermore, the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) as well as the contents of ascorbate and glutathione changed in the concentration-dependent manner under NaCl stress. Altogether, our data showed the execution of programmed cell death (PCD), the ROS dynamics, and the behaviors of organelles especially mitochondria and chloroplasts in the cellular responses of peppermint to NaCl stress which can be used for the tolerance screening, and contributed to the understanding of the cellular responses and molecular mechanisms of peppermint to salinity stress, providing the theoretic basis for the further development and utilization of peppermint in saline areas. PMID:25388000

  9. A possible NaCl pathway in the bioregenerative human life support system

    NASA Astrophysics Data System (ADS)

    Polonskiy, V. I.; Gribovskaya, I. V.

    One of the ways to involve NaCl in the mass exchange of the bioregenerative human life support system (BLSS) is to grow some vegetables and leafy greens that can accumulate sodium chloride at high concentrations in their edible biomass. Lettuce, celery cabbage, chard, dill and radish plants were grown hydroponically in Knop's nutrient solution. In the first series of experiments, at the end of the growth period the plants were grown on solutions containing 2-14 g/L of NaCl for 1-5 days. It was found that the amount of sodium in edible biomass of the plants increased with NaCl concentration in the solution and with the time plants were irrigated with that solution. The content of NaCl in the biomass of leaves and edible roots was considerable—up to 10% dry matter. At the same time, the amount of water in the leaves decreased and productivity of the treatment plants was 14-28% lower than that of the control ones, grown on Knop's solution. The treatment plants contained less than half of the amount of nitrates recorded in the control ones. Expert evaluation showed that the taste of the vegetables and leafy greens of the treatment group were not inferior to the taste of the control plants. In the second series of experiments, prior to being grown on the NaCl solution, the plants were irrigated with water for 2, 4 or 6 days. It was found that lower salt status of the plants was not favorable for increased salt accumulation in their biomass. If a human consumes 30 g salad vegetables and follows a low-sodium diet (3 g/d of table salt), it may be feasible to recycle NaCl in the BLSS using vegetables and leafy greens.

  10. Water intake after stomach loads of NaCl in Mongolian gerbils.

    PubMed

    Kozub, F J; Hodges, J; Yutzy, S

    1980-10-01

    Sixty mongolian gerbils (Meriones unguiculatus), 30 male and 30 female, were stomach loaded (2% b.w.) with either water or .9, 2, 6, 10, or 12% NaCl (wt x vol.). Unlike male rats, male gerbils did not lose weight. Female gerbils, like female rats, did not lose weight. However, female gerbils did not increase their water intake at any concentration, whereas males increased their water intake only at the 10 and 12% levels. These data are very much unlike those for the rat (male and female) which show an increase in water intake in response to NaCl solutions above isotonicity. PMID:7441220

  11. Electrochemical Behavior of 2205 Duplex Stainless Steel in NaCl Solution with Different Chromate Contents

    NASA Astrophysics Data System (ADS)

    Luo, H.; Dong, C. F.; Cheng, X. Q.; Xiao, K.; Li, X. G.

    2012-07-01

    The electrochemical behavior of 2205 duplex stainless steel in NaCl solution with different chromate contents were investigated by potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and scanning electron microscope (SEM). The effect of chromate on passivity and pitting behavior of stainless steel was also studied. The results showed that pitting susceptibility as well as semiconducting properties of passive film is heavily dependent on the chromate concentration. There exists a critical chromate value (about 0.03 M in 1 M NaCl solutions) below which the pitting corrosion on the stainless steel would be inhibited and above which it would be accelerated.

  12. Crevice corrosion -- NaCl concentration map for Alloy 625 at elevated temperature

    SciTech Connect

    Amano, Toshiaki; Kojima, Yoichi; Tsujikawa, Shigeo

    1995-12-31

    The repassivation potentials, Er, for metal/metal-crevice of Alloy 625 were determined in 0.3--10% NaCl solutions for temperatures up to 250 C. The ER were found to be the least noble at temperatures around 100 and 125 C. The Er became more noble as temperature increased; this tendency was particularly strong in diluted solutions. Based on the experimental data, a crevice corrosion map showing the critical condition in terms of temperature and NaCl concentration was presented. As for the map, a wide repassivation region was found in elevated temperatures, similar to that of commercially pure titanium, C.P.Ti.

  13. Crevice corrosion - NaCl concentration map for grade-2 titanium at elevated temperature

    SciTech Connect

    Tsujikawa, Shigeo; Kojima, Yoichi

    1993-12-31

    The repassivation potential, ER, for metal/metal-crevice of Commercially Pure Titanium, C.P.Ti, was determined in NaCl solutions at temperatures up to 250C. The ER has its least noble value near 100C and becomes more noble as the temperature increases. As shown in previous research, the shrinkage of the repassivation region should continue with increasing temperatures. However, in conducting this same experiment at temperatures higher than 100C, an examination of the NaCl concentration - temperature - crevice corrosion map verifies that the repassivation region began to expand again when the temperature exceeded 140C. This expansion continued as the temperature continued to increase.

  14. Effect of NaCl on the accumulation of glycerol by three Aspergillus species.

    PubMed

    Zidan, M A; Abdel-Mallek, A Y

    1987-01-01

    The accumulation of glycerol was investigated in three Aspergillus species, A. niger, A. ochraceus and A. tamarii after being grown in media containing different NaCl concentrations. Intra-extracellular as well as total glycerol were markedly accumulated by the three organisms in response to increased salinity. However, at salinity levels of 10-14% NaCl, extracellular glycerol was somewhat lowered. In addition, it was found that the maximum accumulation of glycerol in A. niger and A. tamarii was reached within the first 10 hours after salinization. However, after desalinization, the extracellular glycerol was continuously increased within the first 6 hours at the expense of intracellular glycerol. PMID:3449615

  15. Reactions of NaCl with Gaseous SO3, SO2, and O2

    NASA Technical Reports Server (NTRS)

    Fielder, W. L.; Stearns, C. A.; Kohl, F. J.

    1983-01-01

    Hot corrosion of gas turbine engine components involves deposits of Na2SO4 which are produced by reactions between NaCl and oxides of sulfur. For the present investigation, NaCl single crystals were exposed at 100 to 850 C to gaseous mixtures of SO3, SO2, and O2. The products formed during this exposure depend, primarily, on the temperatures. The four product films were: NaCl-SO3; Na2S2O7; Na2SO4; and NaCl-Na2SO4. The kinetics of the reactions were measured.

  16. Reactions of chromium with gaseous NaCl in an oxygen environment

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.

    1976-01-01

    Target collection techniques and high pressure mass spectrometric sampling have been used to study the formation of volatile chromium-containing species in the reaction of Cr2O3 with O2 and NaCl gases. Experiments were performed at atmospheric pressure as a function of chromium temperature, oxygen pressure, and NaCl gas concentration. The major chromium-containing vapor species were found to be (NaCl)x CrO3 gas, with x = 1,2, and 3, which are products of heterogeneous reactions on the surface. The kinetics indicate first order dependence on oxygen and sodium chloride pressures.

  17. Role of Trichoderma harzianum in mitigating NaCl stress in Indian mustard (Brassica juncea L) through antioxidative defense system

    PubMed Central

    Ahmad, Parvaiz; Hashem, Abeer; Abd-Allah, Elsayed Fathi; Alqarawi, A. A.; John, Riffat; Egamberdieva, Dilfuza; Gucel, Salih

    2015-01-01

    Salinity stress affected crop production of more than 20% of irrigated land globally. In the present study the effect of different concentrations of NaCl (0, 100, and 200 mM) on growth, physio-biochemical attributes, antioxidant enzymes, oil content, etc. in Brassica juncea and the protective role of Trichoderma harzianum (TH) was investigated. Salinity stress deteriorates growth, physio-biochemical attributes, that ultimately leads to decreased biomass yield in mustard seedlings. Higher concentration of NaCl (200 mM) decreased the plant height by 33.7%, root length by 29.7% and plant dry weight (DW) by 34.5%. On the other hand, supplementation of TH to NaCl treated mustard seedlings showed elevation by 13.8, 11.8, and 16.7% in shoot, root length and plant DW respectively as compared to plants treated with NaCl (200 mM) alone. Oil content was drastically affected by NaCl treatment; however, TH added plants showed enhanced oil percentage from 19.4 to 23.4% in the present study. NaCl also degenerate the pigment content and the maximum drop of 52.0% was recorded in Chl. ‘a’. Enhanced pigment content was observed by the application of TH to NaCl treated plants. Proline content showed increase by NaCl stress and maximum accumulation of 59.12% was recorded at 200 mM NaCl. Further enhancement to 70.37% in proline content was recorded by supplementation of TH. NaCl stress (200 mM) affirms the increase in H2O2 by 69.5% and MDA by 36.5%, but reduction in the accumulation is recorded by addition of TH to mustard seedlings. 200 mM NaCl elevated SOD, POD, APX, GR, GST, GPX, GSH, and GSSG in the present study. Further enhancement was observed by the application of TH to the NaCl fed seedlings. NaCl stress suppresses the uptake of important elements in both roots and shoots, however, addition of TH restored the elemental uptake in the present study. Mustard seedlings treated with NaCl and TH showed restricted Na uptake as compared to seedlings treated with NaCl alone. In

  18. Structural forms of cubic BC2N

    SciTech Connect

    Sun, Hong; Jhi, Seung-Hoon; Roundy, David; Cohen, Marvin L.; Louie, Steven G.

    2001-03-01

    Superhard cubic boron-carbonitrides (c-BC2N) are studied with the use of the ab initio pseudopotential density functional method. The total energy, lattice constant, bulk and shear moduli, and electronic band structures as well as the electron density of states are calculated for all the possible c-BC2N structures in an eight-atom zinc-blende-structured cubic unit cell. The results obtained provide a plausible explanation for recent experimental observations as well as a possible path to synthesis of the materials.

  19. Quadratic-Like Dynamics of Cubic Polynomials

    NASA Astrophysics Data System (ADS)

    Blokh, Alexander; Oversteegen, Lex; Ptacek, Ross; Timorin, Vladlen

    2016-02-01

    A small perturbation of a quadratic polynomial f with a non-repelling fixed point gives a polynomial g with an attracting fixed point and a Jordan curve Julia set, on which g acts like angle doubling. However, there are cubic polynomials with a non-repelling fixed point, for which no perturbation results into a polynomial with Jordan curve Julia set. Motivated by the study of the closure of the Cubic Principal Hyperbolic Domain, we describe such polynomials in terms of their quadratic-like restrictions.

  20. Purely cubic action for string field theory

    NASA Technical Reports Server (NTRS)

    Horowitz, G. T.; Lykken, J.; Rohm, R.; Strominger, A.

    1986-01-01

    It is shown that Witten's (1986) open-bosonic-string field-theory action and a closed-string analog can be written as a purely cubic interaction term. The conventional form of the action arises by expansion around particular solutions of the classical equations of motion. The explicit background dependence of the conventional action via the Becchi-Rouet-Stora-Tyutin operator is eliminated in the cubic formulation. A closed-form expression is found for the full nonlinear gauge-transformation law.

  1. Gustatory Plasticity in "C. elegans" Involves Integration of Negative Cues and NaCl Taste Mediated by Serotonin, Dopamine, and Glutamate

    ERIC Educational Resources Information Center

    Hukema, Renate K.; Rademakers, Suzanne; Jansen, Gert

    2008-01-01

    While naive "Caenorhabditis elegans" individuals are attracted to 0.1-200 mM NaCl, they become strongly repelled by these NaCl concentrations after prolonged exposure to 100 mM NaCl. We call this behavior gustatory plasticity. Here, we show that "C. elegans" displays avoidance of low NaCl concentrations only when pre-exposure to NaCl is combined…

  2. Study of the nanobubble phase of aqueous NaCl solutions by dynamic light scattering

    NASA Astrophysics Data System (ADS)

    Bunkin, N. F.; Shkirin, A. V.; Burkhanov, I. S.; Chaikov, L. L.; Lomkova, A. K.

    2014-11-01

    Aqueous NaCl solutions with different concentrations have been investigated by dynamic scattering of laser radiation. It is experimentally shown that these solutions contain scattering particles with a wide size distribution in a range of ~10 - 100 nm. The experimental results indirectly confirm the existence of quasi-stable gas nanobubbles in the bulk of aqueous ionic solutions.

  3. Fabrication of large binary colloidal crystals with a NaCl structure

    PubMed Central

    Vermolen, E. C. M.; Kuijk, A.; Filion, L. C.; Hermes, M.; Thijssen, J. H. J.; Dijkstra, M.; van Blaaderen, A.

    2009-01-01

    Binary colloidal crystals offer great potential for tuning material properties for applications in, for example, photonics, semiconductors and spintronics, because they allow the positioning of particles with quite different characteristics on one lattice. For micrometer-sized colloids, it is believed that gravity and slow crystallization rates hinder the formation of high-quality binary crystals. Here, we present methods for growing binary colloidal crystals with a NaCl structure from relatively heavy, hard-sphere-like, micrometer-sized silica particles by exploring the following external fields: electric, gravitational, and dielectrophoretic fields and a structured surface (colloidal epitaxy). Our simulations show that the free-energy difference between the NaCl and NiAs structures, which differ in their stacking of the hexagonal planes of the larger spheres, is very small (≈0.002 kBT). However, we demonstrate that the fcc stacking of the large spheres, which is crucial for obtaining the pure NaCl structure, can be favored by using a combination of the above-mentioned external fields. In this way, we have successfully fabricated large, 3D, oriented single crystals having a NaCl structure without stacking disorder. PMID:19805259

  4. Study of the nanobubble phase of aqueous NaCl solutions by dynamic light scattering

    SciTech Connect

    Bunkin, N F; Shkirin, A V; Burkhanov, I S; Chaikov, L L; Lomkova, A K

    2014-11-30

    Aqueous NaCl solutions with different concentrations have been investigated by dynamic scattering of laser radiation. It is experimentally shown that these solutions contain scattering particles with a wide size distribution in a range of ∼10 – 100 nm. The experimental results indirectly confirm the existence of quasi-stable gas nanobubbles in the bulk of aqueous ionic solutions. (light scattering)

  5. Single PTCDA molecules on planar and stepped KCl and NaCl(100) surfaces

    NASA Astrophysics Data System (ADS)

    Aldahhak, H.; Schmidt, W. G.; Rauls, E.

    2015-11-01

    First principles calculations have been employed to investigate the adsorption of single PTCDA molecules on KCl(100) and NaCl(100) surfaces. The lateral and rotational diffusion barriers as well as the electronic and the geometric aspects of single PTCDA molecules adsorbed on planar terraces as well as at defective steps have been studied in detail.

  6. Adsorption of PTCDA on NaCl(100) and KCl(100)

    NASA Astrophysics Data System (ADS)

    Aldahhak, H.; Schmidt, W. G.; Rauls, E.

    2013-11-01

    The adsorption of PTCDA on KCl and NaCl(100) surfaces has been investigated by means of first principles calculations. Besides a variety of adsorbate structures for single molecules and a monolayer of flat lying molecules on plain terraces, the influence of monoatomic steps and the different defect site at step edges has been studied in detail.

  7. Purinergic mechanisms of lateral parabrachial nucleus facilitate sodium depletion-induced NaCl intake.

    PubMed

    Menezes, Miguel F; Barbosa, Silas P; De Andrade, Carina A F; Menani, José V; De Paula, Patrícia M

    2011-02-01

    Purinergic receptors are present in the lateral parabrachial nucleus (LPBN), a pontine structure involved in the control of sodium intake. In the present study, we investigated the effects of α,β-methyleneadenosine 5'-triphosphate (α,β-methylene ATP, selective P2X purinergic agonist) alone or combined with pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS, P2X purinergic antagonist) or suramin (non-selective P2 purinergic antagonist) injected into the LPBN on sodium depletion-induced 1.8% NaCl intake. Male Holtzman rats with stainless steel cannulas implanted into the LPBN were used. Sodium depletion was induced by treating rats with the diuretic furosemide (20mg/kg of body weight) followed by 24h of sodium-deficient diet. Bilateral injections of α,β-methylene ATP (2.0 and 4.0nmol/0.2μl) into the LPBN increased sodium depletion-induced 1.8% NaCl intake (25.3±0.8 and 26.5±0.9ml/120min, respectively, vs. saline: 15.2±1.3ml/120min). PPADS (4nmol/0.2μl) alone into the LPBN did not change 1.8% NaCl intake, however, pretreatment with PPADS into the LPBN abolished the effects of α,β-methylene ATP on 1.8% NaCl intake (16.9±0.9ml/120min). Suramin (2.0nmol/0.2μl) alone into the LPBN reduced sodium depletion-induced 1.8% NaCl intake (5.7±1.9ml/120min, vs. saline: 15.5±1.1ml/120min), without changing 2% sucrose intake or 24h water deprivation-induced water intake. The combination of suramin and α,β-methylene ATP into the LPBN produced no change of 1.8% NaCl intake (15.2±1.2ml/120min). The results suggest that purinergic P2 receptor activation in the LPBN facilitates NaCl intake, probably by restraining LPBN mechanisms that inhibit sodium intake. PMID:21129366

  8. NaCl reflection coefficients in proximal tubule apical and basolateral membrane vesicles. Measurement by induced osmosis and solvent drag.

    PubMed

    Pearce, D; Verkman, A S

    1989-06-01

    Two independent methods, induced osmosis and solvent drag, were used to determine the reflection coefficients for NaCl (sigma NaCl) in brush border and basolateral membrane vesicles isolated from rabbit proximal tubule. In the induced osmosis method, vesicles loaded with sucrose were subjected to varying inward NaCl gradients in a stopped-flow apparatus. sigma NaCl was determined from the osmolality of the NaCl solution required to cause no initial osmotic water flux as measured by light scattering (null point). By this method sigma NaCl was greater than 0.92 for both apical and basolateral membranes with best estimates of 1.0. sigma NaCl was determined by the solvent drag method using the Cl-sensitive fluorescent indicator, 6-methoxy-N-[3-sulfopropyl]quinolinium (SPQ), to detect the drag of Cl into vesicles by inward osmotic water movement caused by an outward osmotic gradient. sigma NaCl was determined by comparing experimental data with theoretical curves generated using the coupled flux equations of Kedem and Katchalsky. By this method we found that sigma NaCl was greater than 0.96 for apical and greater than 0.98 for basolateral membrane vesicles, with best estimates of 1.0 for both membranes. These results demonstrate that sigma NaCl for proximal tubule apical and basolateral membranes are near unity. Taken together with previous results, these data suggest that proximal tubule water channels are long narrow pores that exclude NaCl. PMID:2765660

  9. Use of Pom Pons to Illustrate Cubic Crystal Structures.

    ERIC Educational Resources Information Center

    Cady, Susan G.

    1997-01-01

    Describes a method that uses olefin pom pons to illustrate cubic crystal structure. Facilitates hands-on examination of different packing arrangements such as hexagonal close-packed and cubic close-packed structures. (JRH)

  10. Cubic Polynomials with Rational Roots and Critical Points

    ERIC Educational Resources Information Center

    Gupta, Shiv K.; Szymanski, Waclaw

    2010-01-01

    If you want your students to graph a cubic polynomial, it is best to give them one with rational roots and critical points. In this paper, we describe completely all such cubics and explain how to generate them.

  11. Sound velocity anisotropy in cubic crystals

    NASA Technical Reports Server (NTRS)

    Tsang, T.; Park, H. Y.

    1983-01-01

    Simple analytical expressions may be derived for sound velocities in cubic crystals by using lattice harmonics or functions which are invariant under the crystal symmetry operations. These expressions are in good agreement with the exact results for typical crystals such as metallic iron and potassium fluoride.

  12. A monotonicity conjecture for real cubic maps

    SciTech Connect

    Dawson, S.P.; Galeeva, R.; Milnor, J.; Tresser, C.

    1993-12-01

    This will be an outline of work in progress. We study the conjecture that the topological entropy of a real cubic map depends ``monotonely`` on its parameters, in the sense that each locus of constant entropy in parameter space is a connected set. This material will be presented in more detail in a later paper.

  13. [Effect of 5-aminolevulinic acid on photosynthetic characteristics of tomato seedlings under NaCl stress].

    PubMed

    Zhao, Yan-Yan; Yan, Fei; Hu, Li-Pan; Zhou, Xiao-Ting; Zou, Zhi-Rong

    2014-10-01

    In this research, the possibility of exogenous application of 5-aminolevulinic acid (ALA) on photosynthetic characteristics of tomato seedlings under NaCl stress was investigated. Five leaves seedlings of tomato (Solanum lycopersicum cv. Jinpeng No. 1) were used as starting materials, applied with 50 mg · L(-1) ALA by foliage spray or 10 mg · L(-1) ALA by root soaking to study the changes in their photosynthesis and fluorescence parameters under 100 mmol · L(-1) NaCl. The result showed that, photosynthetic gas exchange parameters (net photosynthetic rate P,, stomata conductance g(s), intercellular CO2 concentration Ci, transpiration Tr) and chlorophyll fluorescence parameters (Fv'/Fm', Fm', ΦPS II, ETR, qP, Pc) were severely reduced under NaCl treatment and ALA application by foliage spray or root soaking with proper concentrations exerted positive influences on tomato seedlings under salt stress, while there were some differences between foliage spray and root soaking in the influence on chlorophyll content, photosynthesis and chlorophyll fluorescence. Both foliage spray with 50 mg · L(-1) ALA and root soaking with 10 mg L(-1) ALA significantly increased Pn, Ci, g(s) and Tr of tomato seedlings under NaCl stress, alleviated photosynthetic inhibition. Root application of ALA had a better effect on the chlorophyll content than foliage application. However, the photosynthetic parameters showed that foliage application of ALA had a better effect than root application, and both treatments had no difference in the influence on chlorophyll fluorescence parameters of tomato seedlings. It could be deduced that the regulating effect of ALA on enhancing salt tolerance of tomato seedlings is attributed to its effect on improving chlorophyll biosynthesis and metabolism, increasing stomatal conductance and reducing stomatal limitation, thus, enhancing the photosynthetic capacity and PS II photochemical efficiency of tomato leaves under NaCl stress. PMID:25796901

  14. Effects of various dopants on NaCl and KCl glow curves

    NASA Astrophysics Data System (ADS)

    Davidson, A. T.; Kozakiewicz, A. G.; Derry, T. E.; Comins, J. D.; Suszynska, M.

    2004-06-01

    We have measured the thermoluminescence of a number of NaCl and KCl crystals following irradiation at ambient temperature with the same dose (10 kGy) of Co-60 γ rays. We compare the TL of pure samples and of samples doped with europium and calcium ions. In the case of NaCl, additional impurities (Ni, Pb, Sr and Cr) have been investigated. The effects of irradiation are determined using optical absorption and thermoluminescence. Factors investigated include the effects of different dopants on TL glow curves and the effects of thermal annealing samples at 400 °C before the irradiation. Changes in TL glow curves relating to changes in the state of aggregation of the impurities produced by pre-irradiation annealing are reported in this paper. Perhaps the most significant effect is a temperature shift of the main glow peak in pre-annealed compared to not pre-annealed samples in the case of Eu doped NaCl. The magnitude of the shift depends on the concentration of the Eu dopant. Shifts are also observed for Ni and Sr impurities in NaCl, but not for Ca and Cr impurities in NaCl. In the case of KCl, glow peaks generally occur at similar temperatures in doped samples and do not shift when doped samples are pre-annealed. Here the main effect of different impurities is to influence the size of the emission and not the structure of the glow curve. Results are discussed in terms of current theories of thermoluminescence.

  15. [Physiological response and salt-tolerance of Gleditsia microphylla under NaCl stress].

    PubMed

    Lu, Bin; Hou, Yue-min; Li, Xin-yang; Chang, Yue-xia; Huang, Da-zhuang; Lu, Bing-she

    2015-11-01

    In order to exploit the salt-tolerance ability and mechanism of Gleditsia microphylla, the plant growth, cell membrane permeability, the activities of cell protective enzymes, and the distri- butions of Na+ and K+ in different tissues were investigated under various NaCl stress (0.053%, 0.15%, 0.3%, 0.45% and 0.6%) with potted two-year seedlings. The results were as follows: With the increase of NaCl concentration, the seedling growth decreased while the salt injured index in- creased, and the salt-tolerance thresholds of seedling was 0.42% NaCl. With the NaCl concentration increasing, the membrane permeability, superoxide anion radical generating rate and MDA content increased grandly, while the activities of SOD, POD and CAT demonstrated an increase-decrease curve which reached the peak at 0.3% or 0.45%. Under the high salt stress condition, the supero- xide anion could be consumed timely by increasing the activities of SOD, POD and CAT enzymes, which was useful to avoid cell injure. Under salt stress condition, the Na+ content in different tissues increased gradually, following the order of root > leaf > stem, and the K+ content and K+/Na+ in different tissues decreased, following the order of leaf > root > stem. The K+-Na+ selective transpor- tation coefficients (S(K+) · Na+) of stem and leaf tissues under the soil NaCl stress condition were both increased, following the order of leaf > stem. In conclusion, the findings suggested that the salt- adaptation mechanisms of G. microphylla were root salt-rejection by Na+ accumulation and restriction in root tissue and leaf salt-tolerance by a remarkably increased ability of K+ selective absorption and accumulation in leaf tissue. PMID:26915182

  16. Acoustic band gaps of three-dimensional periodic polymer cellular solids with cubic symmetry

    NASA Astrophysics Data System (ADS)

    Chen, Yanyu; Yao, Haimin; Wang, Lifeng

    2013-07-01

    The band structure and sound attenuation of the triply periodic co-continuous composite materials with simple cubic lattice, body-centered cubic lattice, and face-centered cubic lattice consisting of PMMA and air are investigated using finite element method. Complete band gaps are found in these structures and the width of band gaps is depending on volume fraction. It is shown that the width of band gaps along different directions in the first irreducible Brillouin zone enlarges as the volume fraction increases from 0.2 to 0.7. The largest complete band gap widths of the three types of co-continuous structures are 0.29, 0.54, and 0.55, respectively. As the complete band gaps appear in audible range of frequencies, these triply periodic co-continuous composite materials can be utilized to control noise.

  17. Low-field NMR determination of water distribution in meat batters with NaCl and polyphosphate addition.

    PubMed

    Shao, Jun-Hua; Deng, Ya-Min; Jia, Na; Li, Ru-Ren; Cao, Jin-Xuan; Liu, Deng-Yong; Li, Jian-Rong

    2016-06-01

    The objective was to elucidate the influence of NaCl and polyphosphates in the stage of protein swelling on the water-holding capacity (WHC) of meat batter. The meat batters were formulated with salt in different ways by adding established amounts of only NaCl, only polyphosphates, jointly adding NaCl and polyphosphates, and a control without any salt. An increase (p<0.05) in water retention was found when a combination of NaCl and polyphosphates was used. A high textural parameter was observed in the two treatments with NaCl, but not in the group with only polyphosphate. For the polyphosphate group, T22 was lower (p<0.05) than in the other three before heating; however, after heating, T21 and T22 were both significantly decreased, and a new component emerged, T23, which was significantly lower than the others. For the NaCl treatment, heated or not, T22 was always the highest. It was revealed that NaCl had affected the WHC by increasing the mobility and distribution of water, particularly with polyphosphate, but polyphosphate could not be an equal substitute for NaCl given its resulting lowest textural properties and poor microstructure. By presenting different hydration states in the protein swelling stage, the meat batter qualities were differentiated. PMID:26830593

  18. Effect of NaCl on heat resistance, antibiotic susceptibility, and Caco-2 cell invasion of Salmonella.

    PubMed

    Yoon, Hyunjoo; Park, Beom-Young; Oh, Mi-Hwa; Choi, Kyoung-Hee; Yoon, Yohan

    2013-01-01

    This study evaluated the effects of NaCl on heat resistance, antibiotic susceptibility, and Caco-2 cell invasion of Salmonella. Salmonella typhimurium NCCP10812 and Salmonella enteritidis NCCP12243 were exposed to 0, 2, and 4% NaCl and to sequential increase of NaCl concentrations from 0 to 4% NaCl for 24 h at 35°C. The strains were then investigated for heat resistance (60°C), antibiotic susceptibility to eight antibiotics, and Caco-2 cell invasion efficiency. S. typhimurium NCCP10812 showed increased thermal resistance (P < 0.05) after exposure to single NaCl concentrations. A sequential increase of NaCl concentration decreased (P < 0.05) the antibiotic sensitivities of S. typhimurium NCCP10812 to chloramphenicol, gentamicin, and oxytetracycline. NaCl exposure also increased (P < 0.05) Caco-2 cell invasion efficiency of S. enteritidis NCCP12243. These results indicate that NaCl in food may cause increased thermal resistance, cell invasion efficiency, and antibiotic resistance of Salmonella. PMID:23936782

  19. Final-state symmetry of Na 1s core-shell excitons in NaCl and NaF

    SciTech Connect

    Nagle, K.P.; Seidler, G.T.; Shirley, E.L.; Fister, T.T.; Bradley, J.A.; Brown, F.C.

    2009-08-13

    We report measurements of the Na 1s contribution to the nonresonant inelastic x-ray scattering (NRIXS) from NaCl and NaF. Prior x-ray absorption studies have observed two pre-edge excitons in both materials. The momentum-transfer dependence (q dependence) of the measured NRIXS cross section and of real-space full multiple scattering and Bethe-Salpeter calculations determine that the higher-energy core excitons are s type for each material. The lower-energy core excitons contribute at most weakly to the NRIXS signal and we propose that these may be surface core excitons, as have been observed in several other alkali halides. The analysis of the orbital angular momentum of these features leads to a discussion of the limited sensitivity of NRIXS measurements to d-type final states when investigating 1s initial states. In this case the s- and p-type final density of states can be characterized by measurements at a small number of momentum transfers. This is in contrast to the case of more complex initial states for which measurements at a large number of momentum transfers are needed to separate the rich admixture of accessible and contributing final-state symmetries.

  20. Strength and Mechanical Response of NaCl Using In-Situ Transmission Electron Microscopy Compression and Nanoindentation.

    PubMed

    Lin, Kai-Peng; Fang, Te-Hua; Kang, Sho-Hui

    2016-03-01

    Strength and mechanical properties of single crystal sodium chloride (NaCl) are characterized. Critical deformation variations of NaCl pillared structures and films are estimated using in-situ transmission electron microscope (TEM) compression tests and nanoindentation experiments. Young's modulus and contact stiffness of NaCl pillars with diameters of 300 to 500 nm were 10.4-23.9 GPa, and 159-230 N/m, respectively. The nanohardness and Vickers hardness of the NaCl (001) film were 282-596 and 196-260 MPa, respectively. The results could provide useful information for understanding the mechanical properties, contact and local deformation of NaCl pillars and films. PMID:27455676

  1. Characteristics of injury and recovery of net NO3- transport of barley seedlings from treatments of NaCl

    NASA Technical Reports Server (NTRS)

    Klobus, G.; Ward, M. R.; Huffaker, R. C.

    1988-01-01

    The nature of the injury and recovery of nitrate uptake (net uptake) from NaCl stress in young barley (Hordeum vulgare L, var CM 72) seedlings was investigated. Nitrate uptake was inhibited rapidly by NaCl, within 1 minute after exposure to 200 millimolar NaCl. The duration of exposure to saline conditions determined the time of recovery of NO3- uptake from NaCl stress. Recovery was dependent on the presence of NO3- and was inhibited by cycloheximide, 6-methylpurine, and cerulenin, respective inhibitors of protein, RNA, and sterol/fatty acid synthesis. These inhibitors also prevented the induction of the NO3- uptake system in uninduced seedlings. Uninduced seedlings exhibited endogenous NO3- transport activity that appeared to be constitutive. This constitutive activity was also inhibited by NaCl. Recovery of constitutive NO3- uptake did not require the presence of NO3-.

  2. Defect-induced hyper-Raman spectra in cubic zirconia

    SciTech Connect

    Shin, S.; Ishigame, M.

    1986-12-15

    Hyper-Raman scattering of cubic zirconia and CaF/sub 2/ is measured at room temperature. For a CaF/sub 2/ crystal, the frequencies of the TO and LO modes with T/sub 1//sub u/ symmetry are determined to be 260 and 480 cm/sup -1/, which are in good accord with the results of infrared measurements. In a fluorite-type cubic zirconia, the defect-induced hyper-Raman spectra due to the oxygen vacancies are observed. The structures of the hyper-Raman spectra are reasonably explained by the frequency distribution of hyper-Raman-active modes in the whole Brillouin zone, which is estimated from the imaginary part of the simple projections of the phonon displacement-displacement Green's functions onto a defect space consisting of an O/sub 6/ molecule. From the analysis of the mode vectors for the O/sub 6/ molecule, the attempt frequency of oxygen ions is found to correspond to the 690-cm/sup -1/ band in the observed hyper-Raman spectra with T/sub 1//sub u/ symmetry.

  3. Nano-Engineered Cubic Zirconia for Orthopaedic Implant Applications

    NASA Astrophysics Data System (ADS)

    Namavar, F.; Rubinstein, A.; Sabirianov, R.; Thiele, G.; Sharp, J.; Pokharel, U.; Namavar, R.; Garvin, K.

    2012-02-01

    Osseointegration failure of the prosthesis prevents long-term stability, which contributes to pain, implant loosening, and infection that usually necessitates revision surgery. Cell attachment and spreading in vitro is generally mediated by adhesive proteins such as fibronectin and vitronectin. We designed and produced pure cubic zirconia (ZrO2) ceramic coatings by ion beam assisted deposition (IBAD) with nanostructures comparable to the size of proteins. Our ceramic coatings exhibit high hardness and a zero contact angle with serum. In contrast to Hydroxyapatite (HA), nano-engineered zirconia films possess excellent adhesion to all orthopaedic materials. Adhesion and proliferation experiments were performed with a bona fide mesenchymal stromal cells cell line (OMA-AD). Our experimental results indicated that nano-engineered cubic zirconia is superior in supporting growth, adhesion, and proliferation. We performed a comparative analysis of adsorption energies of the FN fragment using quantum mechanical calculations and Monte Carlo simulation on both types of surfaces: smooth and nanostructured. We have found that the initial FN fragment adsorbs significantly stronger on the nanostructured surface than on the smooth surface.

  4. Differential tolerance of 3 self-rooted Citrus limon cultivars to NaCl stress.

    PubMed

    Tsabarducas, V; Chatzistathis, T; Therios, I; Koukourikou-Petridou, M; Tananaki, C

    2015-12-01

    One-year-old self-rooted cuttings of three Citrus limon cultivars (Nouvel Athos, Lisbon, Maglini) were grown in 1 L black plastic bags, containing a mixture of sand: perlite (1:1), in order to investigate: i) if genotypic differences to salt stress existed, ii) if KNO3 can alleviate salinity stress, iii) the role of carbohydrates (such as the sugars fructose, glucose and sucrose) and proline as possible osmoregulators in C. limon osmoprotection, and iv) if genotypic differences to salt stress tolerance exist among the 3 studied cultivars. The experiment included 3 treatments: i) control (C), i.e. 25% modified Hoagland (No2) solution (MHS)-NaCl, ii) T1, 25% MHS+80 mM NaCl, iii) T2, 25% MHS+80 mM NaCl+5 mM KNO3. Plant growth was negatively affected by high NaCl (T1); the highest Cl and Na quantities have been absorbed by Lisbon, while the lowest ones by Maglini. Salt stress reduced macronutrient and Zn concentrations, as well as the total carbohydrate concentration, and increased peroxidase (POD) activity and chlorophyll fluorescence in the leaves of the 3 C. limon cultivars studied; five mM KNO3 application alleviated the harmful effect of salt stress on leaf total carbohydrate concentration and leaf N and K concentrations. Sucrose was dramatically reduced in all the three genotypes studied, while leaf fructose concentration was significantly increased in Nouvel Nouvel Nouvel Athos and Maglini under salt stress. Leaf proline concentration of Maglini was significantly decreased by the high NaCl concentration, while Nouvel Athos and Lisbon had high proline concentration in their leaves. In conclusion, from the significantly decreased levels of proline for Maglini, together with the greatest reduction of the ratio Fv/Fm and the least enhancement of POD activity-compared to the other two cultivars-it can be concluded that Maglini was more susceptible to salinity, and should not be preferred for cultivation under NaCl stress. Finally, rich KNO3 application

  5. Spectroscopic measurements of the pH in NaCl brines

    NASA Astrophysics Data System (ADS)

    Millero, Frank J.; DiTrolio, Benjamin; Suarez, Andres F.; Lando, Gabriele

    2009-06-01

    Spectrophotometric measurements of the pH in natural waters such as seawater have been shown to yield precise results. In this paper, the sulfonephthalein indicator m-cresol purple ( mCP, H 2I) has been used to determine the pH of NaCl brines. The indicator has been calibrated in NaCl solutions from 5 to 45 °C and ionic strengths from 0.03 to 5.5 m. The calibrations were made using TRIS buffers (0.03 m, TRIS/TRIS-HCl) with known dissociation constants pK TRIS in NaCl solutions [Foti C., Rigano C. and Sammartano S. (1999) Analysis of thermodynamic data for complex formation: protonation of THAM and fluoride ion at different temperatures and ionic strength. Ann. Chim. 89, 1-12]. The values of pH were determined from pH=pK+log{(R-e1)/(e2-Re3)} where R = 578A/ 434A, the ratios of the indicator absorbance maximum at 578 and 434 nm, e1 = 0.00691, e2 = 2.222 and e3 = 0.1331 [Clayton T. and Byrne R. H. (1993) Spectrophotometric seawater pH measurements: total hydrogen ion concentration scale calibration of m-cresol purple and at-sea results. Deep-Sea Res. 40, 2115-2129]. Measurements were also made in NaCl solutions with different levels of TRIS (0.01-0.11 m). At low levels of TRIS buffer (<0.03 m), the values of pK mCP increased significantly. This effect can lead to erroneous values of pK mCP at low ionic strengths in estuaries and lakes. The measured values of pK mCP in NaCl as a function of ionic strength ( I/m) and temperature ( T/K) were fitted to the equation ( σ = 0.0072) pK=-29.095+2639.2/T+5.0417lnT-0.3307I0.5-186.80I0.5/T-0.28346I+296.44I/T+0.12841I1.5-68.23I1.5/T These results should be useful in determining the pH of NaCl brines in natural waters from 0 to 50 °C.

  6. 46 CFR 160.049-2 - Types and sizes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Types and sizes. (a) Type. Buoyant cushions shall be of the box type, i.e., have top, bottom, and gusset... than 225 square inches of top surface area, shall contain not less than 630 cubic inches of...

  7. 46 CFR 160.049-2 - Types and sizes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Types and sizes. (a) Type. Buoyant cushions shall be of the box type, i.e., have top, bottom, and gusset... than 225 square inches of top surface area, shall contain not less than 630 cubic inches of...

  8. 46 CFR 160.049-2 - Types and sizes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Types and sizes. (a) Type. Buoyant cushions shall be of the box type, i.e., have top, bottom, and gusset... than 225 square inches of top surface area, shall contain not less than 630 cubic inches of...

  9. Fluid evolution in the H 2O-CH 4-CO 2-NaCl system during emerald mineralization at Gravelotte, Murchison Greenstone Belt, Northeast Transvaal, South Africa

    NASA Astrophysics Data System (ADS)

    Nwe, Yin Yin; Morteani, Giulio

    1993-01-01

    Fluid evolution during emerald mineralization at the Gravelotte emerald mine has been studied by microthermometry and laser Raman microprobe spectrometry. The emeralds and associated phenakites occur on the flanks of a highly metasomatised albitite pegmatoid body and in the biotite schists at and near its contact. The fluids lie in the H 2O-CH 4-CO 2-NaCl system and four types of inclusions are characterised based on time of trapping and fluid contents. The earliest type 1 inclusions, found in phenakites and the emeralds which formed from them, are low salinity (<6 wt% NaCl) with up to 18 mol% CH 4. The carbonic phase contains over 93 mol% CH 4 and variable small amounts of CO 2, C 2H 6, N 2, and H 2S. The solvus crest for this system lies at ≈400°C, closer to the H 2O end of the join. With time the fluids become less CH 4 rich and more saline. The type 2 fluids are highly variable in both CH 4-CO 2 contents and salinity, reflecting mixing of type 1 fluids with higher salinity brines. The late type 3 and 4 inclusions are CH 4-CO 2-free high salinity inclusions with up to 38 wt% NaCl. Trapping conditions for the type 1 fluids were around 450-500°C and 4 kb based on model isochores and geologic evidence. During the trapping of type 2 inclusions, fluid pressures probably fluctuated due to opening and resealing of fractures. Approximate P- T ranges of trapping for these and other later inclusions have been defined, minimum trapping temperatures for types 2, 3, and 4 being, respectively, 250, 150, and 240°C, and pressures in the range of 1-4 kb. Calculations of ƒ O 2 show an initial low ƒ O 2 between QFM and the synthetic graphite-CH 4 buffer for the type 1 fluids. This rises to above QFM in the later stages. Such low initial values are uncharacteristic of granitic pegmatite systems, and it is suggested that the phenakites formed in the post-magmatic stage of alkali metasomatism when the albitization took place. In the later stages, phenakite was converted to

  10. Cosmological evolution with the cubic order field derivative coupling

    NASA Astrophysics Data System (ADS)

    Minamitsuji, Masato

    2016-03-01

    We investigate cosmological evolution in the scalar-tensor theory with the field derivative coupling to the double-dual of the Riemann tensor (the cubic-type theory). The theory can be seen as the straightforward extension of the scalar-tensor with the quadratic order field derivative coupling to the Einstein tensor (the quadratic-type theory). Both the field derivative couplings to the Einstein tensor and the double-dual of the Riemann tensor have been argued in terms of the successful realization of the self-tuning of the cosmological constant within the Horndeski theory. Assuming the constant potential given by the sum of the cosmological constant and the quantum vacuum energy, the shift symmetry for the scalar field and no matter fields, in the spatially-flat Friedmann-Lemaître-Robertson-Walker spacetime, we can reduce the set of the field equations to the first-order ordinary nonlinear differential equation for the Hubble parameter, showing the existence of the self-tuned and runaway de Sitter solutions, in addition to the standard de Sitter solutions in general relativity and the finite Hubble singularities which can be reached within the finite time. We then argue the possible cosmological evolution in terms of the values of the effective cosmological constant, the kinetic coupling constants and the initial Hubble parameter. Although the behavior of the universe around each of the de Sitter solutions as well as the finite time singularities is very similar in both theories, we find that the crucial difference appears in terms of no bounce or turnaround behavior across the vanishing Hubble parameter as well as no limitation for the range of the Hubble parameter in the cubic-type theory.

  11. Wavelets based on Hermite cubic splines

    NASA Astrophysics Data System (ADS)

    Cvejnová, Daniela; Černá, Dana; Finěk, Václav

    2016-06-01

    In 2000, W. Dahmen et al. designed biorthogonal multi-wavelets adapted to the interval [0,1] on the basis of Hermite cubic splines. In recent years, several more simple constructions of wavelet bases based on Hermite cubic splines were proposed. We focus here on wavelet bases with respect to which both the mass and stiffness matrices are sparse in the sense that the number of nonzero elements in any column is bounded by a constant. Then, a matrix-vector multiplication in adaptive wavelet methods can be performed exactly with linear complexity for any second order differential equation with constant coefficients. In this contribution, we shortly review these constructions and propose a new wavelet which leads to improved Riesz constants. Wavelets have four vanishing wavelet moments.

  12. Face-Centered-Cubic Nanostructured Polymer Foams

    NASA Astrophysics Data System (ADS)

    Cui, C.; Baughman, R. H.; Liu, L. M.; Zakhidov, A. A.; Khayrullin, I. I.

    1998-03-01

    Beautifully iridescent polymer foams having Fm-3m cubic symmetry and periodicities on the scale of the wavelength of light have been synthesized by the templating of porous synthetic opals. These fabrication processes involve the filling of porous SiO2 opals (with typical cubic lattice parameters of 250 nm) with either polymers or polymer precursors, polymerization of the precursors if necessary, and removal of the fcc array of SiO2 balls to provide an all-polymer structure. The structures of these foams are similar to periodic minimal surfaces, although the Gaussian curvature can have both positive and negative values. Depending upon whether the internal surfaces of the opal are polymer filled or polymer coated, the polymer replica has either one or two sets of independent channels. We fill these channels with semiconductors, metals, or superconductors to provide electronic and optical materials with novel properties dependent on the nanoscale periodicity.

  13. Solubility of NaCl in aqueous electrolyte solutions from 10 to 100°C

    USGS Publications Warehouse

    Clynne, M.A.; Potter, R.W., II; Haas, J.L., Jr.

    1981-01-01

    The solubilities of NaCl in aqueous KCl, MgCl2, CaCl2, and mixed CaCl2-KCl solutions have been determined from 10 to 100??C. The data were fit to an equation, and the equation was used to calculate values of the change in solubility of NaCl, ???[NaCl]/???T. These values are required for calculations of the rate of migration of fluids in a thermal gradient in rock salt. The data obtained here indicate that the values of ???[NaCl]/???T are 36-73% greater for solutions containing divalent ions than for the NaCl-H2O system.

  14. Thermodynamic and Transport Properties of H2O + NaCl from Polarizable Force Fields.

    PubMed

    Jiang, Hao; Mester, Zoltan; Moultos, Othonas A; Economou, Ioannis G; Panagiotopoulos, Athanassios Z

    2015-08-11

    Molecular dynamics and Monte Carlo simulations were performed to obtain thermodynamic and transport properties of the binary H2O + NaCl system using the polarizable force fields of Kiss and Baranyai ( J. Chem. Phys. 2013 , 138 , 204507 and 2014 , 141 , 114501 ). In particular, liquid densities, electrolyte and crystal chemical potentials of NaCl, salt solubilities, mean ionic activity coefficients, vapor pressures, vapor-liquid interfacial tensions, and viscosities were obtained as functions of temperature, pressure, and salt concentration. We compared the performance of the polarizable force fields against fixed-point-charge (nonpolarizable) models. Most of the properties of interest are better represented by the polarizable models, which also remain physically realistic at elevated temperatures. PMID:26574461

  15. Structure and orientation of small particles of platinum deposited on NaCl and mica

    NASA Technical Reports Server (NTRS)

    Renou, A.; Gillet, M.

    1979-01-01

    The structure of small platinum particles condensed in vacuum onto NaCl (001), NaCl (111) and mica substrates was studied by electron diffraction and electron microscopy. Results show that above a certain substrate temperature decahedral or icosahedral particles are formed. These particles are practically absent with substrates cleaved in high vacuum. They are always much less numerous than in gold films prepared under the same conditions. Assumptions made to explain this phenomenon are: (1) the initial growth of an abnormal structure of the nuclei as opposed by the substrate; (2) the particles disappear before they attain a size which corresponds to the observations; and (3) the particles result from a coalescence mechanism leading to multiple twinned particles.

  16. VizieR Online Data Catalog: VY CMa ALMA NaCl images (Decin+, 2016)

    NASA Astrophysics Data System (ADS)

    Decin, L.; Richards, A. M. S.; Millar, T. J.; Baudry, A.; de, Beck E.; Homan, W.; Smith, N.; van de Sande, M.; Walsh, C.

    2016-07-01

    VY CMa was observed for ALMA Science Verification on 2013 16-19 August using 16-20 12-m antennas on baselines from 0.014-2.7km. The main objective was to map the H2O maser lines at 321 and 325GHz (Band 7) and 658GHz (Band 9), but several thermal lines identified with various rotational transitions of NaCl, TiO2, SO2, and SiO were also present in the spectral setting in addition to the continuum data. Four NaCl lines in the ground or first vibrational state are covered in the ALMA band 7 data. All of them are detected, albeit only two are unblended (see Table 1). (3 data files).

  17. Corrosion Behavior of Titanium Grade 7 in Fluoride-Containing NaCl Brines

    SciTech Connect

    Lian, T; Whalen, M T; Wong, L

    2004-10-25

    The effects of fluoride on the corrosion behavior of Titanium Grade 7 (0.12-0.25% Pd) have been investigated. Up to 0.1 mol/L fluoride was added to the NaCl brines at 95 C, and three pH values of 4, 8, and 11 were selected for studying pH dependence of fluoride effects. It was observed that fluoride significantly altered the anodic polarization behavior, at all three pH values of 4, 8, and 11. Under acidic condition fluoride caused active corrosion. The corrosion of Titanium grade 7 was increased by three orders of magnitude when a 0.1 mol/L fluoride was added to the NaCl brines at pH 4, and the Pd ennoblement effect was not observed in acidic fluoride-containing environments. The effects of fluoride were reduced significantly when pH was increased to 8 and above.

  18. Effect of Acacia Gum, NaCl, and Sucrose on Physical Properties of Lotus Stem Starch.

    PubMed

    Puri, Ritika; Gill, Balmeet Singh; Khetra, Yogesh

    2014-01-01

    Consumer preferences in east Asian part of the world pave the way for consumption of lotus stem starch (LSS) in preparations such as breakfast meals, fast foods, and traditional confectioneries. The present study envisaged the investigation and optimization of additives, that is, acacia gum, sodium chloride (NaCl), and sucrose, on water absorption (WA), water absorption index (WAI), and water solubility index (WSI) of LSS employing response surface methodology (RSM). Acacia gum resulted in increased water uptake and swelling of starch; however, NaCl reduced the swelling power of starch by making water unavailable to starch and also due to starch-ion electrostatic interaction. Sucrose restricted the water absorption by binding free water and decreased amylose leaching by building bridges with starch chains and thus forming rigid structure. PMID:26904639

  19. Enhancement of corrosion resistance of carbon steel by Dioscorea Hispida starch in NaCl

    NASA Astrophysics Data System (ADS)

    Zulhusni, M. D. M.; Othman, N. K.; Lazim, Azwan Mat

    2015-09-01

    Starch is a one of the most abundant natural product in the world and has the potential as corrosion inhibitor replacing harmful synthetic chemical based corrosion inhibitor. This research was aimed to examines the potential of starch extracted from local Malaysian wild yam (Dioscorea hispida), as corrosion inhibitor to carbon steel in NaCl media replicating sea water. By using gravimetric test and analysis, in which the carbon steel specimens were immersed in NaCl media for 24, 48 and 60 hours with the starch as corrosion inhibitor. the corrosion rate (mmpy) and inhibition efficiencies (%) was calculated. The results obtained showed decrease in corrosion rate as higher concentration of starch was employed. The inhibition efficiencies also shows an increasing manner up to 95.97 % as the concentration of the inhibitor increased.

  20. Adsorptive removal of methylene blue by agar: effects of NaCl and ethanol

    PubMed Central

    2012-01-01

    Adsorption of methylene blue (MB) on agar was investigated as a function of temperature (308-328 K), different concentrations of NaCl and HCl and various weight percentages of binary mixtures of ethanol with water. It was observed that the maximum experimental adsorption capacity, qm, exp, in water is up to 50 mg g-1 and decreases with increase in weight percentage of ethanol and NaCl and HCl concentration compared to that of water. Analysis of data using ARIAN model showed that MB adsorbs as monomer and dimer on the surface of agar. Binding constants of MB to agar were calculated using the Temkin isotherm. The process is exothermic in water and other solutions. The mean adsorption energy (E) value indicated binding of MB to agar is chemical adsorption. Kinetics of this interaction obeys from the pseudo-second-order model and diffusion of the MB molecules into the agar is the main rate-controlling step. PMID:22339759

  1. Effect of Acacia Gum, NaCl, and Sucrose on Physical Properties of Lotus Stem Starch

    PubMed Central

    Gill, Balmeet Singh

    2014-01-01

    Consumer preferences in east Asian part of the world pave the way for consumption of lotus stem starch (LSS) in preparations such as breakfast meals, fast foods, and traditional confectioneries. The present study envisaged the investigation and optimization of additives, that is, acacia gum, sodium chloride (NaCl), and sucrose, on water absorption (WA), water absorption index (WAI), and water solubility index (WSI) of LSS employing response surface methodology (RSM). Acacia gum resulted in increased water uptake and swelling of starch; however, NaCl reduced the swelling power of starch by making water unavailable to starch and also due to starch-ion electrostatic interaction. Sucrose restricted the water absorption by binding free water and decreased amylose leaching by building bridges with starch chains and thus forming rigid structure. PMID:26904639

  2. Deposition Of Cubic BN On Diamond Interlayers

    NASA Technical Reports Server (NTRS)

    Ong, Tiong P.; Shing, Yuh-Han

    1994-01-01

    Thin films of polycrystalline, pure, cubic boron nitride (c-BN) formed on various substrates, according to proposal, by chemical vapor deposition onto interlayers of polycrystalline diamond. Substrate materials include metals, semiconductors, and insulators. Typical substrates include metal-cutting tools: polycrystalline c-BN coats advantageous for cutting ferrous materials and for use in highly oxidizing environments-applications in which diamond coats tend to dissolve in iron or be oxidized, respectively.

  3. The Influence of NaCl Crystallization on the Long-Term Mechanical Behavior of Sandstone

    NASA Astrophysics Data System (ADS)

    Zheng, Hong; Feng, Xia-Ting; Jiang, Quan

    2015-01-01

    Salt precipitation can occur in saline aquifers when the pore-fluid concentration exceeds saturation during carbon dioxide sequestration, especially in the dry-out region closest to the wellbore. Results from uniaxial and triaxial compression tests, creep tests, and poromechanical tests indicate that NaCl crystallization in pores enhances the compressive strength and bulk modulus under the given confining pressure, and reduces creep. In addition, it makes the pore liquid pressure in the sandstone less sensitive to changes in the hydrostatic stress under undrained conditions. A poro-viscoelastic model with crystals in the pores is proposed to quantitatively estimate the influence of in-pore NaCl crystallization on the long-term mechanical behavior of sandstone. By considering the thermodynamics of crystallization, a geometrical model of a crystal in a pore space is applied to the quasi-static equilibrium state of the crystallization. The solid-liquid interfacial energy is introduced to provide a convenient approach to couple the mechanical properties of sandstone (as a porous material) and the thermochemistry of the in-pore NaCl crystallization. By adding the solid-liquid interfacial energy, the Clausius-Duhem inequality for the skeleton is established for the viscoelasticity based on the proposed geometrical model of a crystal in the pore space. The constitutive equations are deduced from the free energy balance relationship to evaluate the influence of crystallization on the effective stress in terms of the solid-liquid interfacial energies and the pore-size distribution. By comparing the model's output with the test results, it is found that the poro-viscoelastic model describes the influence of in-pore NaCl crystallization on the long-term mechanical behavior of the sandstone reasonably well.

  4. Body Temperatures During Exercise in Deconditioned Dogs: Effect of NACL and Glucose Infusion

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Kruk, B.; Nazar, K.; Kaciuba-Usciko, H.

    2000-01-01

    Infusion of glucose (Glu) into normal exercising dogs attenuates the rise in rectal temperature (Delta-Tre) when compared with delta-Tre during FFA infusion or no infusion. Rates of rise and delta-=Tre levels are higher during exercise after confinement. Therefore, the purpose of this study was to determine if Glu infusion would attenuate the exercise-induced excess hyperthermia after deconditioning. Rectal and quadricep femoris muscle temperatures (Tmu) were measured in 7 male, mongrel dogs dogs (19.6 +/- SD 3.0 kg) during 90 minutes of treadmill exercise (3.1 +/-SD 0.2 W/kg) with infusion (30ml/min/kg) of 40% Glu or 0.9% NaCL before BC) and after confinement (AC) in cages (40 x 110 x 80 cm) for 8 wk. Mean (+/-SE body wt. were 19.6 +/- 1.1 kg BC and 19.5 +/- 1.1kg AC, exercise VO2 were not different (40.0 - 42.0 mi/min/kg-1). With NaCl AC, NaCl BC, GluAC, and GluBC: Delta-Tre were, 1.8, 1.4, 1.3 and 0.9C respectively; and Delta-Tmu were 2.3, 1.9, 1.6, and 1.4C. respectively (P<0.05 from GluBC). Compared with NaCl infusion, attenuated both Delta-Tre and Delta-Tmu BC and AC, respectively. Compared with GluBC, GluAC attenuated Delta-Tmu but not Delta-Tre. Thus. with similar heat production, the mechanism for attenuation at bad body temperature with Glu infusion must affect avenues of heat dissipation.

  5. Selective adsorption of 4He on the NaCl(001) surface

    NASA Astrophysics Data System (ADS)

    Leung, W. Y.; Larese, J. Z.; Frankl, D. R.

    1984-01-01

    The diffraction of 4He nozzle beams at several energies from cleaved (001) surfaces of NaCl has been studied. Resonance features are identified and give binding energies of 4.1 ± 0.1, 1.5 ± 0.1 and 0.3 ± 0.15 meV. One feature suggests an energy of 5 meV, but this is unsubstantiated. The resonance signatures are in disagreement with elastic scattering theories.

  6. [Water in oil microemulsions containing NaCl for transdermal delivery of fluorouracil].

    PubMed

    Xiao, Yan-Yu; Liu, Fang; Chen, Zhi-Peng; Ping, Qi-Neng

    2011-06-01

    This study is to prepare the W/O microemulsion containing NaCl and fluorouracil (5-Fu) as a model drug to investigate the transdermal characteristics and skin irritation of the microemulsion in vitro. Isopropylmyristate (IPM) acting as oil phase, Aerosol-OT (AOT) as surfactant, Tween 85 as cosurfactant, NaCl solution was added dropwise to the oil phase to prepare W/O microemulsion at room temperature using magnetic stirring, and then 5-Fu powder was added. According to the area of microemulsion based on the pseudo-tertiary phase diagrams, the optimum formulation was screened initially. And the permeation flux of fluorouracil across excised mice skin was determined in vitro using Franz diffusion cells to study the influence of the amount of water and the drug loading capacity and optimize the formulation further. Refer to 5-Fu cream, the irritation of microemulsion on the rat skin was studied. The optimum formulation was composed of 0.7% (w/v) 5-Fu, 50% NaCl solution (0.05 mol x L(-1)), 20% mix-surfactant (AOT/Tween 85, K(m) = 2) and 29.3% oil (IPM). The cumulative amount of fluorouracil permeated in 12 h was (2 013.4 +/- 41.6) microg x cm(-2), 20.23 folds and 10.38 folds more than 0.7% fluorouracil aqueous solution and 2.5% (w/w) fluorouracil cream, respectively. Microemulsion exhibited some irritation, but could be reversed after drug withdrawal. The addition of NaCl significantly increased the content of water and the drug loading in microemulsion systems. The NaCl/AOT-Tween 85/IPM microemulsion system promoted the permeation of fluorouracil greatly, which may be a promising vehicle for the transdermal delivery of fluorouracil and other hydrophilic drug. PMID:21882535

  7. Method of synthesizing cubic system boron nitride

    SciTech Connect

    Yuzu, S.; Sumiya, H.; Degawa, J.

    1987-10-13

    A method is described for synthetically growing cubic system boron nitride crystals by using boron nitride sources, solvents for dissolving the boron nitride sources, and seed crystals under conditions of ultra-high pressure and high temperature for maintaining the cubic system boron nitride stable. The method comprises the following steps: preparing a synthesizing vessel having at least two chambers, arrayed in order in the synthesizing vessel so as to be heated according to a temperature gradient; placing the solvents having different eutectic temperatures in each chamber with respect to the boron nitride sources according to the temperature gradient; placing the boron nitride source in contact with a portion of each of the solvents heated at a relatively higher temperature and placing at least a seed crystal in a portion of each of the solvents heated at a relatively lower temperature; and growing at least one cubic system boron nitride crystal in each of the solvents in the chambers by heating the synthesizing vessel for establishing the temperature gradient while maintaining conditions of ultra-high pressure and high temperature.

  8. Thermoelastic properties of rock-salt NaCl at high pressures and temperatures

    NASA Astrophysics Data System (ADS)

    Santos, M. L. M.; Shukla, G.; Wentzcovitch, R. M.

    2014-12-01

    Rock-salt NaCl is an important mineral in our daily lives, in high pressure science/technology, and in the oil/gas industry. The latter has come to prominence since the discovery of deep water pre-salt structures containing great hydrocarbon reserves out of the SE coast of Brazil. The unique aspects of these regions, such as deep water (greater than 2 km below sea level) and deep hydrocarbon reserves (more than 5 km deep) are challenging for oil/gas explorations. Oil/gas field imaging algorithms require good velocity models for seismic wave-propagation within the salt layer. Despite its importance, there is still insufficient information on the elasticity of and sound velocities in NaCl at relevant P,T conditions. Here we report such properties in rock-salt NaCl at relevant P,T conditions as obtained by first principles (DFT) quasiharmonic calculations. We compare intermediate and final results with available experimental data on thermodynamics and thermoelastic properties and combine them for optimum accuracy. These results should be useful for and facilitate imaging pre-salt hydrocarbon reserves. Research supported by CAPES from Brazil, NSF/DMR, and NSF/EAR.

  9. Fluorescence properties of biochemicals in dry NaCl composite aerosol particles and in solutions

    NASA Astrophysics Data System (ADS)

    Putkiranta, M.; Manninen, A.; Rostedt, A.; Saarela, J.; Sorvajärvi, T.; Marjamäki, M.; Hernberg, R.; Keskinen, J.

    2010-06-01

    Several fluorophores, such as tryptophan, NADH, NADPH, and riboflavin are found in airborne micro-organisms. In this work, the fluorescence properties of these biochemicals were studied both in dry NaCl composite aerosol particles and in saline solutions by means of laser-induced fluorescence. Fluorescence spectra were measured from individual, airborne aerosol particles and from solutions in cuvette. The excitation wavelength was varied in steps from 210 nm to 419 nm and the fluorescence was detected within a wavelength band of 310-670 nm. For each sample, the measured fluorescence emission spectra were combined into fluorescence maps. The fluorescence maximum of riboflavin in a dry NaCl composite particle is 20 nm red-shifted compared with the solution, whereas the maxima are blue-shifted by about 25 nm for tryptophan and 15 nm for NADH and NADPH. The molecular fluorescence cross sections have significant differences between the aerosol particles and the solutions, except for tryptophan. For NADH and NADPH the cross sections are over 20 times larger in the aerosol particles than in the solutions probably as a result of partial quenching of fluorescence in solution caused by the collision or stacking with the adenine moiety. The fluorescence cross section of riboflavin is almost 60 times larger in the solution than in the dry NaCl composite aerosol. This is probably caused by the different microenvironment around the fluorophore molecule and by the concentration quenching in the particles where the fluorescing molecules are relatively close to each other.

  10. Strength and equation of state of NaCl from radial x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Xiong, Lun; Bai, Ligang; Liu, Jing

    2014-01-01

    The strength and equation of state of NaCl were determined under nonhydrostatic compression up to 27 GPa using an energy-dispersive radial x-ray diffraction technique in a diamond-anvil cell using the lattice strain theory. Together with estimation of the high-pressure shear modulus, it is suggested that NaCl could support a maximum differential stress of 0.980 GPa at 22.6 GPa under uniaxial compression. The differential stress rapidly drops at 27.2 GPa due to the phase transition from B1 phase to B2 phase for NaCl. The hydrostatic compression data of B1 phase yield a bulk modulus K0 = 25.6(8) GPa and its pressure derivative K0' = 5.16(20) using Pt pressure scale. In addition, a comparative study of the observed pressures from Pt scale and ruby-fluorescence scale shows that the ruby-fluorescence pressures may reflect the lower stress state under nonhydrostatic compression compared with hydrostatic compression.

  11. Effects of dilute aqueous NaCl solution on caffeine aggregation

    SciTech Connect

    Sharma, Bhanita; Paul, Sandip

    2013-11-21

    The effect of salt concentration on association properties of caffeine molecule was investigated by employing molecular dynamics simulations in isothermal-isobaric ensemble of eight caffeine molecules in pure water and three different salt (NaCl) concentrations, at 300 K temperature and 1 atm pressure. The concentration of caffeine was taken almost at the solubility limit. With increasing salt concentration, we observe enhancement of first peak height and appearance of a second peak in the caffeine-caffeine distribution function. Furthermore, our calculated solvent accessible area values and cluster structure analyses suggest formation of higher order caffeine cluster on addition of salt. The calculated hydrogen bond properties reveal that there is a modest decrease in the average number of water-caffeine hydrogen bonds on addition of NaCl salt. Also observed are: (i) decrease in probability of salt contact ion pair as well as decrease in the solvent separated ion pair formation with increasing salt concentration, (ii) a modest second shell collapse in the water structure, and (iii) dehydration of hydrophobic atomic sites of caffeine on addition of NaCl.

  12. Effects of dilute aqueous NaCl solution on caffeine aggregation

    NASA Astrophysics Data System (ADS)

    Sharma, Bhanita; Paul, Sandip

    2013-11-01

    The effect of salt concentration on association properties of caffeine molecule was investigated by employing molecular dynamics simulations in isothermal-isobaric ensemble of eight caffeine molecules in pure water and three different salt (NaCl) concentrations, at 300 K temperature and 1 atm pressure. The concentration of caffeine was taken almost at the solubility limit. With increasing salt concentration, we observe enhancement of first peak height and appearance of a second peak in the caffeine-caffeine distribution function. Furthermore, our calculated solvent accessible area values and cluster structure analyses suggest formation of higher order caffeine cluster on addition of salt. The calculated hydrogen bond properties reveal that there is a modest decrease in the average number of water-caffeine hydrogen bonds on addition of NaCl salt. Also observed are: (i) decrease in probability of salt contact ion pair as well as decrease in the solvent separated ion pair formation with increasing salt concentration, (ii) a modest second shell collapse in the water structure, and (iii) dehydration of hydrophobic atomic sites of caffeine on addition of NaCl.

  13. Knudsen Cell Uptake Experiments of Oxides of Nitrogen on Fractional Layers of NaCl.

    NASA Astrophysics Data System (ADS)

    Hoffman, R. C.; Finlayson-Pitts, B. J.

    2002-12-01

    Sea salt aerosols rich in NaCl play important roles in heterogeneous chemistry occurring in the troposphere. Understanding the kinetics and mechanisms of these processes is essential to understanding the extent of the tropospheric halogen budget. Two such reactions involve HNO3 and N2O5 reacting with NaCl to generate photochemically inert HCl and photochemically active ClNO2, respectively. The uptake and reaction of HNO3 and N2O5 on NaCl and on synthetic sea salt (SSS) was studied using a Knudsen cell coupled to an electron impact quadrupole mass spectrometer. Experiments were conducted using fractional salt particle layers with average particle sizes of 164, 291, 312, and 428 μm. Fractional particle layers were used in order to minimize the uncertainty of the available reactive surface area due to diffusion of the reactant gas (either HNO3 or N2O5) into multiple salt layers. Reaction probabilities, found to differ by a factor of 2 between HNO3 and N2O5 for fractional salt layer experiments, will be presented and the atmospheric implications will be discussed.

  14. Relative osmotic effects of raffinose, KCl, and NaCl across basolateral cell membrane.

    PubMed

    Welling, L W; Welling, D J; Ochs, T

    1990-10-01

    Lumen-collapsed segments of rabbit S2 proximal tubule were bathed in isotonic medium and then exposed acutely to a medium made hypertonic by the addition of raffinose, NaCl, KCl, Na gluconate, K gluconate, or choline Cl. The result was a rapid efflux of water and a shrinking of the tubule, which could be measured by video techniques within the first 0.1 s. After reequilibration in isotonic medium, each tubule was then exposed to a second hypertonic medium to provide a direct comparison between two different solutes, either NaCl vs. KCl or raffinose vs. any one of the other solutes. Because raffinose is impermeant across the basolateral cell membrane, the ratio of its effect to that of another solute is a measure of the reflection coefficient (sigma) of that other solute. The following results were obtained: sigma KCl = 0.70 +/- 0.02, sigma K gluconate = 0.97 +/- 0.07, sigma Na gluconate = 0.84 +/- 0.06, and sigma choline Cl = 0.75 +/- 0.06. We previously have reported sigma NaCl = 0.56 +/- 0.07. If sigma of each salt is considered to be the arithmetic average of its component parts, and if gluconate and choline are considered to be impermeant, we also obtain sigma Na+ = 0.68, sigma K+ = 0.94, and sigma Cl- = 0.50. PMID:2221098

  15. Direct Synthesis of Few-Layer Graphene on NaCl Crystals.

    PubMed

    Shi, Liurong; Chen, Ke; Du, Ran; Bachmatiuk, Alicja; Rümmeli, Mark Hermann; Priydarshi, Manish Kumar; Zhang, Yanfeng; Manivannan, Ayyakkannu; Liu, Zhongfan

    2015-12-16

    Chemical vapor deposition is used to synthesize few-layer graphene on micro crystalline sodium chloride (NaCl) powder. The water-soluble nature of NaCl makes it convenient to produce free standing graphene layers via a facile and low-cost approach. Unlike traditional metal-catalyzed or oxygen-aided growth, the micron-size NaCl crystal planes play an important role in the nucleation and growth of few-layer graphene. Moreover, the possibility of synthesizing cuboidal graphene is also demonstrated in the present approach for the first time. Raman spectroscopy, optical microscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy are used to evaluate the quality and structure of the few-layer graphene along with cuboidal graphene obtained in this process. The few-layer graphene synthesized using the present method has an adsorption ability for anionic and cationic dye molecules in water. The present synthesis method may pave a facile way for manufacturing few-layer graphene on a large scale. PMID:26524105

  16. High-temperature corrosion of metallic alloys in an oxidizing atmosphere containing NaCl

    SciTech Connect

    Federer, J.I.

    1989-02-01

    A particular heat-exchanger application involved metallic alloys exposed to flue gases of an aluminum remelt furnace. Because the flue gases might contain NaCl and other halides, the corrosion behavior of the alloys was to be investigated. Planned direct exposure of candidate alloys to the flue gases, however, was not conducted because of premature termination of the project. Complementary laboratory testing was conducted on seven commercially available alloys and two nickel aluminides. These materials were exposed to an oxidizing atmosphere containing 0.06 wt % NaCl for 1100 h at 1000/degree/C. Most of the alloy exhibited grain-boundary attack, which resulted in complete oxidation of enveloped grains. The alloys Incoloy MA-956, Incoloy 800, Inconel 625, Inconel 601, Hastelloy X, Haynes 188, and nickel aluminide IC-50 were substantially more corroded than Alloy 214 and nickel aluminide IC-221. The latter two alloys, therefore, would probably be superior to the others in application involving flue gases containing NaCl. Strength fabricability, and weldability, which are briefly discussed, would also affect selection of materials. 8 refs., 12 figs., 5 tabs.

  17. NaCl alleviates Cd toxicity by changing its chemical forms of accumulation in the halophyte Sesuvium portulacastrum.

    PubMed

    Wali, Mariem; Fourati, Emna; Hmaeid, Nizar; Ghabriche, Rim; Poschenrieder, Charlotte; Abdelly, Chedly; Ghnaya, Tahar

    2015-07-01

    It has previously been shown that certain halophytes can grow and produce biomass despite of the contamination of their saline biotopes with toxic metals. This suggests that these plants are able to cope with both salinity and heavy metal constraints. NaCl is well tolerated by halophytes and apparently can modulate their responses to Cd. However, the underlying mechanisms remain unclear. This study explores the impact of NaCl on growth, Cd accumulation, and Cd speciation in tissues of the halophyte Sesuvium portulacastrum. Seedlings of S. portulacastrum were exposed during 1 month to 0, 25, and 50 μM Cd combined with low salinity (LS, 0.09 mM NaCl) or high salinity (HS, 200 mM NaCl) levels. Growth parameters and total tissue Cd concentrations were determined, in leaves, stems, and root. Moreover, Cd speciation in these organs was assessed by specific extraction procedures. Results showed that, at LS, Cd induced chlorosis and necrosis and drastically reduced plant growth. However, addition of 200 mM NaCl to Cd containing medium alleviated significantly Cd toxicity symptoms and restored plant growth. NaCl reduced the concentration of Cd in the shoots; nevertheless, due to maintenance of higher biomass under HS, the quantity of accumulated Cd was not modified. NaCl modified the chemical form of Cd in the tissues by increasing the proportion of Cd bound to pectates, proteins, and chloride suggesting that this change in speciation is involved in the positive impact of NaCl on Cd tolerance. We concluded that the tolerance of S. portulacastrum to Cd was enhanced by NaCl. This effect is rather governed by the modification of the speciation of the accumulated Cd than by the reduction of Cd absorption and translocation. PMID:25758421

  18. Determination of oxidative stress in wheat leaves as influenced by boron toxicity and NaCl stress.

    PubMed

    Masood, Sajid; Saleh, Livia; Witzel, Katja; Plieth, Christoph; Mühling, Karl H

    2012-07-01

    Boron (B) toxicity symptoms are visible in the form of necrotic spots and may worsen the oxidative stress caused by salinity. Hence, the interactive effects of combined salinity and B toxicity stress on antioxidative activities (TAC, LUPO, SOSA, CAT, and GR) were investigated by novel luminescence assays and standard photometric procedures. Wheat plants grown under hydroponic conditions were treated with 2.5 μM H₃BO₃ (control), 75 mM NaCl, 200 μM H₃BO₃, or 75 mM NaCl + 200 μM H₃BO₃, and analysed 6 weeks after germination. Shoot fresh weight (FW), shoot dry weight (DW), and relative water content (RWC) were significantly reduced, whereas the antioxidative activity of all enzymes was increased under salinity compared with the control. High B application led to necrotic leaf spots but did not influence growth parameters. Following NaCl + B treatment, shoot DW, RWC, SOSA, GR, and CAT activities remained the same compared with NaCl alone, whereas the TAC and LUPO activities were increased under the combined stress compared with NaCl alone. However, shoot FW was significantly reduced under NaCl + B compared with NaCl alone, as an additive effect of combined stress. Thus, we found an adjustment of antioxidative enzyme activity to the interactive effects of NaCl and high B. The stress factor "salt" mainly produced more oxidative stress than that of the factor "high B". Furthermore, addition of higher B in the presence of NaCl increases TAC and LUPO demonstrating that increased LUPO activity is an important physiological response in wheat plants against multiple stresses. PMID:22592001

  19. A combined physicochemical-biological method of NaCl extraction from the irrigation solution in the BTLSS

    NASA Astrophysics Data System (ADS)

    Trifonov, Sergey V.; Tikhomirov, Alexander A.; Ushakova, Sofya; Tikhomirova, Natalia

    2016-07-01

    The use of processed human wastes as a source of minerals for plants in closed biotechnical life support systems (BTLSS) leads to high salt levels in the irrigation solution, as urine contains high concentrations of NaCl. It is important to develop a process that would effectively decrease NaCl concentration in the irrigation solution and return this salt to the crew's diet. The salt-tolerant plants (Salicornia europea) used to reduce NaCl concentration in the irrigation solution require higher salt concentrations than those of the solution, and this problem cannot be resolved by concentrating the solution. At the same time, NaCl extracted from mineralized wastes by physicochemical methods is not pure enough to be included in the crew's diet. This study describes an original physicochemical method of NaCl extraction from the solution, which is intended to be used in combination with the biological method of NaCl extraction by using saltwort plants. The physicochemical method produces solutions with high NaCl concentrations, and saltwort plants serve as a biological filter in the final phase, to produce table salt. The study reports the order in which physicochemical and biological methods of NaCl extraction from the irrigation solution should be used to enable rapid and effective inclusion of NaCl into the cycling of the BTLSS with humans. This study was carried out in the IBP SB RAS and supported by the grant of the Russian Science Foundation (Project No. 14-14-00599).

  20. Chronic effect of NaCl salinity on a freshwater strain of Daphnia magna Straus (Crustacea: Cladocera): a demographic study.

    PubMed

    Martínez-Jerónimo, Fernando; Martínez-Jerónimo, Laura

    2007-07-01

    Daphnia magna is mainly recognized as a freshwater cladoceran, but there are some strains that grow in brackish waters. The tolerance to salinity of a freshwater strain was assessed at NaCl concentrations of 0, 2, 4, 6, and 7 g L(-1). The green microalga Ankistrodesmus falcatus was fed at optimal concentration (4 x 10(5)cells mL(-1)). Reproduction and survival were recorded in two experimental series: in the first one, 20 female neonates were individually studied for each treatment. In the second, cohorts of 10 female neonates were distributed in each of five replicates per treatment. In both cases, experiments were conducted over a full life-cycle. The determined 48-h LC(50) for NaCl was 5.48 g L(-1), but we recorded reproduction at up to 7 g NaCl L(-1). The average clutch size, total progeny, number of clutches, and longevity were significantly reduced by the NaCl concentration (P<0.01); total progeny ranged from 467 to 25 neonates as edge values for NaCl concentrations of 0-7 g L(-1). Inter-brood time was significantly higher for females grown at 7 g NaCl L(-1) (3.9 days). The Life Table analysis demonstrates that average lifespan, life expectancy at birth, net reproductive rate and intrinsic rate of growth were also significantly reduced according to NaCl concentration. Based on the results for the two highest NaCl concentrations (6 and 7 g L(-1)), we conclude that the used D. magna strain was acclimated to develop satisfactorily under concentrations of up to 6 g NaCl L(-1); however, the established salinity conditions reduced significantly reproduction and survival in this strain. PMID:17055052

  1. Epitaxial stabilization of cubic-SiN{sub x} in TiN/SiN{sub x} multilayers

    SciTech Connect

    Soederberg, Hans; Oden, Magnus; Larsson, Tommy; Hultman, Lars; Molina-Aldareguia, Jon M.

    2006-05-08

    The formation of cubic-phase SiN{sub x} is demonstrated in TiN/SiN{sub x} multilayers deposited by reactive dual magnetron sputtering. Transmission electron microscopy examination shows a transition from epitaxially stabilized growth of crystalline SiN{sub x} to amorphous growth as the layer thickness increases from 0.3 to 0.8 nm. The observations are supported by ab initio calculations on different polytypes, which show that the NaCl structure has the best lattice match to TiN. Calculations also reveal a large difference in elastic shear modulus between NaCl-SiN{sub x} and TiN. The results for phase structure and shear modulus offer an explanation for the superhardening effect determined by nanoindentation experiments.

  2. Effects of Nonlocality in Cubic Superconductor V3Si

    NASA Astrophysics Data System (ADS)

    Yethiraj, M.; Christen, D. K.; Paul, D. McK.; Dewhurst, C.; Cubitt, R.

    2004-03-01

    Non-locality in superconductors is an important effect which produces an anisotropic distribution of current flow around the core of a flux-line in the mixed state of a type II superconductor. Such anistropic interactions produce varying forces between the fluxlines as a function of their seperation and hence changes in the symmetry of the flux line lattice (FLL) with field. V3Si has a cubic crystal symmetry and the material shows no evidence of any structure in the energy gap, making this an ideal model system for studies of the influence of "non-locality" on the FLL. We report on the structural changes of the FLL in this clean system with changes in applied field and temperature with particular emphasis on the region near HC2, where this effect weakens. We compare these results with what happens in other systems where nodal structure can also lead to changes in morphology for the FLL.

  3. Lack of effect of peritubular protein on passive NaCl transport in the rabbit proximal tubule.

    PubMed Central

    Berry, C A

    1983-01-01

    The effect of peritubular protein removal on passive NaCl transport was examined in the isolated rabbit proximal convoluted tubule (PCT). Three modes of passive NaCl transport were tested: (a) paracellular backflux of NaCl, (b) convective flow of NaCl through junctional complexes, and (c) anion gradient-dependent NaCl transport. The effect of peritubular protein removal on the paracellular permeability to NaCl was examined using transepithelial specific resistance. Eight PCT were perfused with ultrafiltrate (UF) and bathed in either serum or UF. Transepithelial specific resistance averaged 14.5 +/- 1.9 in the presence and 13.7 +/- 1.7 omega cm2 in the absence of peritubular protein. The effect of peritubular protein removal on the convective flow of a NaCl solution across functional complexes was examined in the absence of active transport by using colloid osmotic pressure (COP) gradients. 12 PCT were perfused with simple salt solutions in Donnan equilibrium with and without protein at 20 degrees C. A COP gradient of 60.1 and -60.1 mmHg drove only 0.06 and -0.23 nl/min, respectively. These values are approximately 10% of the value predicted for an effect of peritubular protein on NaCl solution flow (1.98 nl/min) and are approximately equal to the value predicted for pure water equilibration for the small osmotic pressure difference between solutions in Donnan equilibrium (0.17-0.18 nl/min). The effect of peritubular protein removal on the passive absorption of NaCl driven by anion concentration gradients was examined in seven PCT perfused with a high chloride solution simulating late proximal tubular fluid and bathed in either serum or UF at 20 degrees C. Volume absorption averaged 0.34 +/- 0.20 in the presence and 0.39 +/- 0.20 nl/mm min in the absence of peritubular protein. In conclusion, peritubular protein removal did not significantly affect any of the three distinct modes of passive NaCl transport tested. The lack of effect of peritubular protein removal on

  4. Measurement and Modeling of Mean Activity Coefficients of NaCl in an Aqueous Mixed Electrolyte Solution Containing Glycine

    NASA Astrophysics Data System (ADS)

    Sheikholeslami, Paniz; Dehghani, M. R.; Safahieh, Tina

    2016-08-01

    An electrochemical cell with two ion-selective electrodes (Na+ glass) and (Cl- solid state) was used to measure the mean ionic activity coefficient of NaCl in an aqueous mixture containing NaCl, glycine, and NaNO3 at 308.15 K. The experiments were conducted at fixed molality of NaNO3 (0.1 m) and various molalities of glycine (0-1 m) and NaCl (up to 0.8 m). The experimental data were modeled using a modified version of the Pitzer equation. Finally the activity coefficient ratio of glycine was determined based on the Maxwell equation.

  5. Scattering of helium nozzle beams from LiF/001/ and NaCl/001/ crystal surfaces. I - Elastic and inelastic transitions

    NASA Technical Reports Server (NTRS)

    Bledsoe, J. R.; Fisher, S. S.

    1974-01-01

    Nozzle-type atomic beams and time-of-flight detection methods are employed in studies of the scattering of thermal-energy He-4 atoms from LiF (001) and NaCl (001) surfaces under conditions where diffraction is observed and where substantial inelastic scattering occurs. Intensity and speed-distribution measurements are obtained for the portion of the scattering within the plane of incidence. For these measurements, incident-beam orientation with respect to target (polar angle and azimuth), incident-beam de Broglie wavelength (0.38-0.60 A), and crystal temperature (300-1000 K) are varied. For LiF, the measured intensity distributions exhibit sharp peaks comprised essentially of elastically scattered atoms and corresponding to up to third-order diffraction, inelastic scattering in the form of local dispersion about each of the elastic peaks, and a component of nominally diffuse scattering distributed below and between the peaks. For NaCl, the same general types of scattering are observed, with elastic scattering less prevalent, intensity peaks not as sharp, and dispersions of inelastic scattering harder to resolve.

  6. Design of cubic-phase optical elements using subwavelength microstructures.

    PubMed

    Mirotznik, Mark S; van der Gracht, Joseph; Pustai, David; Mathews, Scott

    2008-01-21

    We describe a design methodology for synthesizing cubic-phase optical elements using two-dimensional subwavelength microstructures. We combined a numerical and experimental approach to demonstrate that by spatially varying the geometric properties of binary subwavelength gratings it is possible to produce a diffractive element with a cubic-phase profile. A test element was designed and fabricated for operation in the LWIR, approximately lambda=10.6 microm. Experimental results verify the cubic-phase nature of the element. PMID:18542199

  7. Solubility of NaCl and KCl in aqueous HCl from 20 to 85°C

    USGS Publications Warehouse

    Potter, Robert W., II; Clynne, Michael A.

    1980-01-01

    The solubilities of NaCl and KCl in aqueous HCl solutions were determined from 20 to 85°C at concentrations ranging from 0 to 20 g of HCl/100 g of solution. Equations are given that describe the solubilities over the range of conditions studied. For NaCl and KCl respectively measured solubilities show an average deviation from these equations of ??0.10 and ??0.08 g/100 g of saturated solution.

  8. A/J and C57BL/6J mice differ in chorda tympani responses to NaCl

    PubMed Central

    Cherukuri, Chandra M.; Bachmanov, Alexander A.; McCaughey, Stuart A.

    2013-01-01

    The molecular mechanisms of sodium taste transduction are not completely understood, especially those responsible for the portion of NaCl’s taste in rodents that is not blocked by amiloride. As a prelude to conducting genetic analyses of peripheral NaCl taste responsiveness, we performed multiunit electrophysiological recordings from the chorda tympani (CT) nerve in C57BL/6J (B6) and A/J mice. Mice were anesthetized, the CT was accessed, and taste solutions were flowed over the tongue in order to measure the integrated whole-nerve response. NaCl was delivered before and during application of 100 μM amiloride. Pre-amiloride responses were significantly larger in A/J than B6 mice for 1–8 mM NaCl. Responses to NaCl were suppressed significantly by amiloride in both strains and to similar degrees. However, the size of the amiloride-insensitive NaCl response component was significantly larger in A/J mice than in B6 mice for NaCl at 2–16 mM. These data help to explain the prior observation that the strains differ in behavioral taste thresholds for NaCl. Specifically, the results suggest that perception of sodium-specific taste by mice depends on the ratio of amiloride-sensitive and -insensitive responses in the CT, rather than on the absolute level of the whole-nerve response to NaCl or on the size of the amiloride-sensitive component alone. Because the B6 and A/J mice differed in the size of their amiloride-insensitive components, they may prove useful in future genetic work designed to characterize the underlying transduction mechanisms. PMID:23458904

  9. Cherenkov and Scintillation Properties of Cubic Zirconium

    NASA Technical Reports Server (NTRS)

    Christl, M.J.; Adams, J.H.; Parnell, T.A.; Kuznetsov, E.N.

    2008-01-01

    Cubic zirconium (CZ) is a high index of refraction (n =2.17) material that we have investigated for Cherenkov counter applications. Laboratory and proton accelerator tests of an 18cc sample of CZ show that the expected fast Cherenkov response is accompanied by a longer scintillation component that can be separated by pulse shaping. This presents the possibility of novel particle spectrometers which exploits both properties of CZ. Other high index materials being examined for Cherenkov applications will be discussed. Results from laboratory tests and an accelerator exposure will be presented and a potential application in solar energetic particle instruments will be discussed

  10. Craniofacial Reconstruction Using Rational Cubic Ball Curves

    PubMed Central

    Majeed, Abdul; Mt Piah, Abd Rahni; Gobithaasan, R. U.; Yahya, Zainor Ridzuan

    2015-01-01

    This paper proposes the reconstruction of craniofacial fracture using rational cubic Ball curve. The idea of choosing Ball curve is based on its robustness of computing efficiency over Bezier curve. The main steps are conversion of Digital Imaging and Communications in Medicine (Dicom) images to binary images, boundary extraction and corner point detection, Ball curve fitting with genetic algorithm and final solution conversion to Dicom format. The last section illustrates a real case of craniofacial reconstruction using the proposed method which clearly indicates the applicability of this method. A Graphical User Interface (GUI) has also been developed for practical application. PMID:25880632

  11. Craniofacial reconstruction using rational cubic ball curves.

    PubMed

    Majeed, Abdul; Mt Piah, Abd Rahni; Gobithaasan, R U; Yahya, Zainor Ridzuan

    2015-01-01

    This paper proposes the reconstruction of craniofacial fracture using rational cubic Ball curve. The idea of choosing Ball curve is based on its robustness of computing efficiency over Bezier curve. The main steps are conversion of Digital Imaging and Communications in Medicine (Dicom) images to binary images, boundary extraction and corner point detection, Ball curve fitting with genetic algorithm and final solution conversion to Dicom format. The last section illustrates a real case of craniofacial reconstruction using the proposed method which clearly indicates the applicability of this method. A Graphical User Interface (GUI) has also been developed for practical application. PMID:25880632

  12. Cubic-quintic long-range interactions with double well potentials

    NASA Astrophysics Data System (ADS)

    Tsilifis, Panagiotis A.; Kevrekidis, Panayotis G.; Rothos, Vassilis M.

    2014-01-01

    In the present work, we examine the combined effects of cubic and quintic terms of the long-range type in the dynamics of a double well potential. Employing a two-mode approximation, we systematically develop two cubic-quintic ordinary differential equations and assess the contributions of the long-range interactions in each of the relevant prefactors, gauging how to simplify the ensuing dynamical system. Finally, we obtain a reduced canonical description for the conjugate variables of relative population imbalance and relative phase between the two wells and proceed to a dynamical systems analysis of the resulting pair of ordinary differential equations. While in the case of cubic and quintic interactions of the same kind (e.g. both attractive or both repulsive), only a symmetry-breaking bifurcation can be identified, a remarkable effect that emerges e.g. in the setting of repulsive cubic but attractive quintic interactions is a ‘symmetry-restoring’ bifurcation. Namely, in addition to the supercritical pitchfork that leads to a spontaneous symmetry breaking of the antisymmetric state, there is a subcritical pitchfork that eventually reunites the asymmetric daughter branch with the antisymmetric parent one. The relevant bifurcations, the stability of the branches and their dynamical implications are examined both in the reduced (ODE) and in the full (PDE) setting. The model is argued to be of physical relevance, especially so in the context of optical thermal media.

  13. Low pressure growth of cubic boron nitride films

    NASA Technical Reports Server (NTRS)

    Ong, Tiong P. (Inventor); Shing, Yuh-Han (Inventor)

    1997-01-01

    A method for forming thin films of cubic boron nitride on substrates at low pressures and temperatures. A substrate is first coated with polycrystalline diamond to provide a uniform surface upon which cubic boron nitride can be deposited by chemical vapor deposition. The cubic boron nitride film is useful as a substitute for diamond coatings for a variety of applications in which diamond is not suitable. any tetragonal or hexagonal boron nitride. The cubic boron nitride produced in accordance with the preceding example is particularly well-suited for use as a coating for ultra hard tool bits and abrasives, especially those intended to use in cutting or otherwise fabricating iron.

  14. Effect of NaCl on the heavy metal tolerance and bioaccumulation of Zygosaccharomyces rouxii and Saccharomyces cerevisiae.

    PubMed

    Li, Chunsheng; Xu, Ying; Jiang, Wei; Dong, Xiaoyan; Wang, Dongfeng; Liu, Bingjie

    2013-09-01

    Application of microorganisms as bioremediators for heavy metal removal in high salt environment is usually restricted by high salt concentrations. The effect of NaCl on the heavy metal tolerance and bioaccumulation of Zygosaccharomyces rouxii and Saccharomyces cerevisiae was investigated. For both yeasts, NaCl improved the cadmium and zinc tolerance, reduced the copper tolerance, and showed no obvious effect on the lead and iron tolerance. The bioaccumulation capacities of copper, zinc, and iron increased but the cadmium bioaccumulation capacities decreased after the addition of NaCl. NaCl obviously affected the amount of heavy metals removed intracellularly and on the cell surface. The heavy metal removal was not overwhelmingly inhibited by elevated NaCl concentrations, especially for Z. rouxii, and in some cases NaCl improved their removal ability. The salt-tolerant Z. rouxii that showed more powerful heavy metal tolerance and removal ability might be more suitable for heavy metal removal in high salt environment. PMID:23774294

  15. Hypertonic NaCl enhances adenosine release and hormonal cAMP production in mouse thick ascending limb.

    PubMed

    Baudouin-Legros, M; Badou, A; Paulais, M; Hammet, M; Teulon, J

    1995-07-01

    Adenosine 3',5'-cyclic monophosphate (cAMP), accumulated in the presence of adenosine, was measured in medullary portions of mouse thick ascending limbs of Henle's loop, suspended either in classic extracellular buffer or in the presence of added NaCl. Under control conditions (140 mmol/l NaCl), adenosine (< 10(-5) mol/l) and N6-cyclohexyladenosine, an A1 adenosine receptor agonist, inhibit the cAMP accumulation induced by arginine vasopressin (AVP). On the other hand, high concentrations of adenosine and CGS-21680, an A2 adenosine receptor agonist, stimulate cAMP formation. Addition of NaCl (+300 mmol/l) to extracellular buffer stimulates the release of endogenous adenosine. It also enhances A2 receptor-induced cAMP accumulation but suppresses A1 receptor-mediated inhibition of adenylyl cyclase. This hypertonic NaCl medium also potentiates the stimulatory action of AVP on adenylyl cyclase. The modifications of tubular responses to both AVP and A1 and A2 agonists, brought about by hypertonic NaCl, were all inhibited by adenosine deaminase, thereby demonstrating the involvement of endogenous adenosine. Adenosine, the release and the effects of which are modulated by hypertonic NaCl, thus appears to act as an endogenous physiological modulator of kidney medulla function. PMID:7631823

  16. NaCl stress impact on the key enzymes in glycolysis from Lactobacillus bulgaricus during freeze-drying.

    PubMed

    Li, Chun; Sun, Jinwei; Qi, Xiaoxi; Liu, Libo

    2015-01-01

    The viability of Lactobacillus bulgaricus in freeze-drying is of significant commercial interest to dairy industries. In the study, L.bulgaricus demonstrated a significantly improved (p < 0.05) survival rate during freeze-drying when subjected to a pre-stressed period under the conditions of 2% (w/v) NaCl for 2 h in the late growth phase. The main energy source for the life activity of lactic acid bacteria is related to the glycolytic pathway. To investigate the phenomenon of this stress-related viability improvement in L. bulgaricus, the activities and corresponding genes of key enzymes in glycolysis during 2% NaCl stress were studied. NaCl stress significantly enhanced (p < 0.05) glucose utilization. The activities of glycolytic enzymes (phosphofructokinase, pyruvate kinase, and lactate dehydrogenase) decreased during freeze-drying, and NaCl stress were found to improve activities of these enzymes before and after freeze-drying. However, a transcriptional analysis of the corresponding genes suggested that the effect of NaCl stress on the expression of the pfk2 gene was not obvious. The increased survival of freeze-dried cells of L. bulgaricus under NaCl stress might be due to changes in only the activity or translation level of these enzymes in different environmental conditions but have no relation to their mRNA transcription level. PMID:26691481

  17. The effect of NaCl on the rheological properties of suspension containing spray dried starch nanoparticles.

    PubMed

    Shi, Ai-min; Li, Dong; Wang, Li-jun; Adhikari, Benu

    2012-11-01

    The effect of NaCl on the rheological properties of suspensions containing spray dried starch nanoparticles produced through high pressure homogenization and emulsion cross-linking technique was studied. Rheological properties such as continuous shear viscosity, viscoelasticity and creep-recovery were measured. NaCl (5-20%, w/w) was found to lower viscosity quite significantly (p<0.05), enhance the heat stability and weaken their gelling behavior compared to starch-only suspension. NaCl reduced both the storage and loss moduli of suspension within the frequency range (0.1-10 rads/s) studied. However, NaCl brought higher speed of reduction on the storage modulus than on the loss modulus, which resulted into large increase in loss angle. The creep-recovery behavior of suspension was affected by NaCl and the recovery rate was highest (86%) at 15% NaCl. The Cross, the Power law and the Burger's models followed the experimental viscosity, storage and loss moduli, and creep-recovery data well with R(2)>0.97. PMID:22944412

  18. The solubility of Th(IV) hydrous oxide in concentrated NaCl and MgCl[sub 2] solutions

    SciTech Connect

    Sterner, S.M.; Felmy, A.R. ); Novak, C.F. )

    1995-09-01

    The solubility of Th(IV) hydrous oxide was studied in concentrated 4m and 6m NaCl solutions as well as in MgCl[sub 2] solutions ranging in concentration from 1m to 3m over a broad range of hydrogen ion concentrations. The observed solubilities in all solutions showed the same trend as observed previously of higher solubilities at early equilibration times, usually 7 to 8 days, followed by decreases in solubility with time as the precipitates aged. The trend of decreasing solubility with time was more pronounced in NaCl solutions than in MgCl[sub 2] solutions. The observed ThO[sub 2](am) solubilities in concentrated NaCl solutions (i.e., 4m and 6m) were lower than previously reported solubilities in more dilute NaCl solutions (i.e., < 3M NaCl). The results in MgCl[sub 2] were similar in all solutions regardless of the MgCl[sub 2] concentration. Current thermodynamic models for the solubility of hydrous thorium, oxide in chloride solutions, which primarily describe only aqueous Th[sup 4+]-Cl[sup -] ion-interactions, predicted higher solubilities than observed in 4 and 6m NaCl as well as in all MgCl[sub 2] solutions. An improved aqueous thermodynamic model, which includes ion-interaction parameters for like charged species, is proposed to explain these results.

  19. The tolerance of Jatropha curcas seedlings to NaCl: an ecophysiological analysis.

    PubMed

    Díaz-López, Leyanes; Gimeno, Vicente; Lidón, Vicente; Simón, Inma; Martínez, Vicente; García-Sánchez, Francisco

    2012-05-01

    Jatropha curcas L. is a biodiesel crop that is resistant to drought stress. However, the salt tolerance of this plant has not yet been studied. To address this question, J. curcas seedlings were grown in a fertilised substrate to evaluate the effects of salinity stress on growth, leaf water relation and organic solutes, leaf and root mineral concentrations, chlorophyll fluorescence parameters, and carbohydrate concentration. The experiment consisted of six treatments with different concentrations of NaCl in the irrigation water: 0 (control), 30, 60, 90, 120 and 150 mM. The total biomass exhibited a salt-induced decrease in the 60 mM or higher NaCl concentrations. The Cl(r) concentration was higher than the Na(+) concentration in all of the plant tissues. The water potential and relative water content of the leaves were not affected by any of the salt treatments. However, salinity induced a decline in the leaf K(+) concentration, together with a significant enhancement in the leaf P, S, Fe, Zn, Mn and Cu levels. The net assimilation of CO₂ also decreased with the salt treatment, due in part to non-stomatal limitation from the increase in C(a)/C(i) and a decrease in the maximum quantum efficiency (F(v)/F(m)) of photosystem II and soil plant analysis development (SPAD) units. This work suggests that J. curcas seedlings exhibit a moderate tolerance to salinity, as the plants were able to tolerate up to 4 dS m(-1) (EC water irrigation; 30 mM NaCl). The negative influences of salinity in this crop are mainly due to Cl(r) and/or Na(+) toxicity and to a nutritional imbalance caused by an increase in the Na(+)/K(+) ratio. The osmotic effect of salinity in this species is negligible, perhaps due to its strong control of leaf transpiration, which reduces water loss. PMID:22377428

  20. Proteomic and Physiological Analyses Reveal Putrescine Responses in Roots of Cucumber Stressed by NaCl.

    PubMed

    Yuan, Yinghui; Zhong, Min; Shu, Sheng; Du, Nanshan; Sun, Jin; Guo, Shirong

    2016-01-01

    Soil salinity is a major environmental constraint that threatens agricultural productivity. Different strategies have been developed to improve crop salt tolerance, among which the effects of polyamines have been well-reported. To gain a better understanding of the cucumber (Cucumis sativus L.) responses to NaCl and unravel the underlying mechanism of exogenous putrescine (Put) alleviating salt-induced damage, comparative proteomic analysis was conducted on cucumber roots treated with NaCl, and/or Put for 7 days. The results showed that exogenous Put restored the root growth inhibited by NaCl. Sixty-two differentially expressed proteins implicated in various biological processes were successfully identified by MALDI-TOF/TOF MS. The four largest categories included proteins involved in defense response (24.2%), protein metabolism (24.2%), carbohydrate metabolism (19.4%), and amino acid metabolism (14.5%). Exogenous Put up-regulated most identified proteins involved in carbohydrate metabolism, implying an enhancement in energy generation. Proteins involved in defense response and protein metabolism were differently regulated by Put, which indicated the roles of Put in stress resistance and proteome rearrangement. Put also increased the abundance of proteins involved in amino acid metabolism. Meanwhile, physiological analysis showed that Put could further up-regulated the levels of free amino acids in salt stressed-roots. In addition, Put also improved endogenous polyamines contents by regulating the transcription levels of key enzymes in polyamine metabolism. Taken together, these results suggest that Put may alleviate NaCl-induced growth inhibition through degradation of misfolded/damaged proteins, activation of stress defense, and the promotion of carbohydrate metabolism to generate more energy. PMID:27471514

  1. Dual mode diffusion of NaCl in Japanese radish under cooking conditions.

    PubMed

    Hashiba, H; Komiyama, J; Nakanishi, T; Gocho, H

    2007-04-01

    Sorption and diffusion of NaCl in Japanese radish have been studied. The sorption isotherm was obtained at 98 degrees C by the conventional method. The concentration profile by the 1-dimensional diffusion of NaCl in Japanese radish from the 3.0% solution was measured at 98 degrees C with the FRITRUC method involving a foodstuff rod in a thin rubber casing. Fick's diffusion coefficient, D, calculated therefrom showed a threefold variation with a maximum. This variation was quantitatively interpreted by applying a dual-mode sorption and diffusion theory under an assumption that the rate determining step of the diffusion is that in the cell wall. Two thermodynamic diffusion coefficients, D(T)(p) and D(T)(L), where p and L are the species of NaCl sorbed by partition and Langmuir modes, respectively, a parameter, alpha, derived from the local equilibrium relations between the p and L species, and S, the concentration of the Langmuir adsorption site in the cell wall of the radish, were estimated. D(T)(p) was found to be smaller than D(T)(L). As an explanation of the larger D(T)(L), we invoked the higher hydration state of the adsorption site of the L species, being ascribed to residual anionic pectin in the radish than the local environment of the p species. The sorption isotherm showed a convex upward deviation from the linear relation. By using the parameters for the local equilibrium and some assumed parameters, the isotherm was found to be explainable. We suggest possible applications of the present method and interpretation to the diffusion study on the cooking systems comprising varieties of seasoning components and foodstuffs. PMID:17995794

  2. How does NaCl improve tolerance to cadmium in the halophyte Sesuvium portulacastrum?

    PubMed

    Mariem, Wali; Kilani, Ben Rjab; Benet, Gunsé; Abdelbasset, Lakdhar; Stanley, Lutts; Charlotte, Poschenrieder; Chedly, Abdelly; Tahar, Ghnaya

    2014-12-01

    Sesuvium portulacastrum is a halophyte with considerable Cd tolerance and accumulation, especially under high salinity. The species seems a good candidate for phytoremediation of Cd-contaminated, saline soils. However, the mechanisms sustaining salt-induced alleviation of Cd toxicity remain unknown. Seedlings of S. portulacastrum were submitted hydroponically to different Cd concentrations (0, 25 and 50 μM Cd) in combination with low (0.09 mM), or high (200 mM) NaCl. Cadmium distribution within leaves and stems was assessed by total Cd, cell sap Cd, and Cd in different cell fractions. In plants with low salt supply (LS) Cd induced severe toxicity. The presence of 200 mM NaCl (HS) significantly alleviated Cd toxicity symptoms. HS drastically reduced both Cd-induced H2O2 production and membrane damage. In HS plants the reduced Cd uptake was only in part responsible for the lower Cd toxicity. Even at equal internal leaf Cd concentrations less Cd toxicity was observed in HS than in LS plants. In HS plants proportionally more Cd was bound in cell walls and proportionally less accumulated in the soluble fraction than in LS plants. Our results show that NaCl improves plant performance under Cd stress by both a decrease of Cd(2+) activity in the medium leading to less Cd uptake and a change of Cd speciation and compartmentation inside tissues. More efficient internal detoxification seems mainly brought about by preferential Cd binding to chloride and cell walls in plants treated with a high salt concentration. PMID:25104648

  3. Proteomic and Physiological Analyses Reveal Putrescine Responses in Roots of Cucumber Stressed by NaCl

    PubMed Central

    Yuan, Yinghui; Zhong, Min; Shu, Sheng; Du, Nanshan; Sun, Jin; Guo, Shirong

    2016-01-01

    Soil salinity is a major environmental constraint that threatens agricultural productivity. Different strategies have been developed to improve crop salt tolerance, among which the effects of polyamines have been well-reported. To gain a better understanding of the cucumber (Cucumis sativus L.) responses to NaCl and unravel the underlying mechanism of exogenous putrescine (Put) alleviating salt-induced damage, comparative proteomic analysis was conducted on cucumber roots treated with NaCl, and/or Put for 7 days. The results showed that exogenous Put restored the root growth inhibited by NaCl. Sixty-two differentially expressed proteins implicated in various biological processes were successfully identified by MALDI-TOF/TOF MS. The four largest categories included proteins involved in defense response (24.2%), protein metabolism (24.2%), carbohydrate metabolism (19.4%), and amino acid metabolism (14.5%). Exogenous Put up-regulated most identified proteins involved in carbohydrate metabolism, implying an enhancement in energy generation. Proteins involved in defense response and protein metabolism were differently regulated by Put, which indicated the roles of Put in stress resistance and proteome rearrangement. Put also increased the abundance of proteins involved in amino acid metabolism. Meanwhile, physiological analysis showed that Put could further up-regulated the levels of free amino acids in salt stressed-roots. In addition, Put also improved endogenous polyamines contents by regulating the transcription levels of key enzymes in polyamine metabolism. Taken together, these results suggest that Put may alleviate NaCl-induced growth inhibition through degradation of misfolded/damaged proteins, activation of stress defense, and the promotion of carbohydrate metabolism to generate more energy. PMID:27471514

  4. Double P2X2/P2X3 Purinergic Receptor Knockout Mice Do Not Taste NaCl or the Artificial Sweetener SC45647

    PubMed Central

    Eddy, Meghan C.; Eschle, Benjamin K.; Barrows, Jennell; Hallock, Robert M.; Finger, Thomas E.

    2009-01-01

    The P2X ionotropic purinergic receptors, P2X2 and P2X3, are essential for transmission of taste information from taste buds to the gustatory nerves. Mice lacking both P2X2 and P2X3 purinergic receptors (P2X2/P2X3Dbl−/−) exhibit no taste-evoked activity in the chorda tympani and glossopharyngeal nerves when stimulated with taste stimuli from any of the 5 classical taste quality groups (salt, sweet, sour, bitter, and umami) nor do the mice show taste preferences for sweet or umami, or avoidance of bitter substances (Finger et al. 2005. ATP signaling is crucial for communication from taste buds to gustatory nerves. Science. 310[5753]:1495–1499). Here, we compare the ability of P2X2/P2X3Dbl−/− mice and P2X2/P2X3Dbl+/+ wild-type (WT) mice to detect NaCl in brief-access tests and conditioned aversion paradigms. Brief-access testing with NaCl revealed that whereas WT mice decrease licking at 300 mM and above, the P2X2/P2X3Dbl−/− mice do not show any change in lick rates. In conditioned aversion tests, P2X2/P2X3Dbl−/− mice did not develop a learned aversion to NaCl or the artificial sweetener SC45647, both of which are easily avoided by conditioned WT mice. The inability of P2X2/P2X3Dbl−/− mice to show avoidance of these taste stimuli was not due to an inability to learn the task because both WT and P2X2/P2X3Dbl−/− mice learned to avoid a combination of SC45647 and amyl acetate (an odor cue). These data suggest that P2X2/P2X3Dbl−/− mice are unable to respond to NaCl or SC45647 as taste stimuli, mirroring the lack of gustatory nerve responses to these substances. PMID:19833661

  5. Radiation damage in NaCl: Calculations with an extended Jain-Lidiard model

    SciTech Connect

    Soppe, W.J.; Prij, J.

    1993-12-31

    The colloid growth due to irradiation in a rock salt formation is calculated with an extended version of the Jain-Lidiard model. The extensions of the model comprise a description of the nucleation stage of the colloids and the role of impurities on the formation of defect centers. Results of model calculations are shown for a representative design for a high-level radioactive waste repository in a rock salt formation. It is concluded that it is unlikely that, near the waste containers, the fraction of NaCl that will be converted to metallic Na and molecular Cl centers will exceed a few mole percent.

  6. Further study of helium diffraction from the NaCl(001) surface

    NASA Astrophysics Data System (ADS)

    Leung, W. Y.; Larese, J. Z.; Frankl, D. R.

    Helium beam scattering has been used to further study the (001) cleavage surface of NaCl. Using a nozzle beam of incident energy 17.6 meV selective adsorption data were measured for a wide range of incidence angles. Resonance data yield energy levels of 4.1 ± 0.1, 1.5 ± 0.1, and 0.31 ± 0.05 meV, in good agreement with our previous results. An intensive search for a lower lying energy level was carried out, but no evidence of its existence was found.

  7. Further study of helium diffraction from the NaCl(001) surface

    NASA Astrophysics Data System (ADS)

    Leung, W. Y.; Larese, J. Z.; Frankl, D. R.

    1984-08-01

    Helium beam scattering has been used to further study the (001) cleavage surface of NaCl. Using a nozzle beam of incident energy 17.6 meV selective adsorption data were measured for a wide range of incidence angles. Resonance data yield energy levels of 4.1 ± 0.1, l.5 ± 0.1. and 0.31 ± 0.05 meV, in good agreement with our previous results. An intensive search for a lower lying energy level was carried out, but no evidence of its existence was found.

  8. Mini-review: regulation of the renal NaCl cotransporter by hormones.

    PubMed

    Rojas-Vega, Lorena; Gamba, Gerardo

    2016-01-01

    The renal thiazide-sensitive NaCl cotransporter, NCC, is the major pathway for salt reabsorption in the distal convoluted tubule. The activity of this cotransporter is critical for regulation of several physiological variables such as blood pressure, serum potassium, acid base metabolism, and urinary calcium excretion. Therefore, it is not surprising that numerous hormone-signaling pathways regulate NCC activity to maintain homeostasis. In this review, we will provide an overview of the most recent evidence on NCC modulation by aldosterone, angiotensin II, vasopressin, glucocorticoids, insulin, norepinephrine, estradiol, progesterone, prolactin, and parathyroid hormone. PMID:26511649

  9. Pulsed, room-temperature operation of a tunable NaCl color-center laser

    SciTech Connect

    Culpepper, C.F.; Carrig, T.J.; Pinto, J.F.; Georgiou, E.; Pollock, C.R.

    1987-11-01

    A room-temperature, pulsed, color-center laser using OH/sup : /-doped NaCl crystals is reported. Crystals were transversely pumped by a Q-switched Nd:YAG laser at 1.06 ..mu..m and produced output energies of 8.6 mJ in 20-nsec pulses. The tuning range extended from 1.37 to 1.77 ..mu..m. During 40 h of operation (>10/sup 6/ pulses), a gradual power fading was observed. Laser action is tentatively ascribed to F/sub 2//sup //sup +/ centers.

  10. Multiply charged monopoles in cubic dimer model

    NASA Astrophysics Data System (ADS)

    Ganesh Jaya, Sreejith; Powell, Stephen

    2015-03-01

    The classical cubic dimer model is a 3D statistical mechanical system whose degrees of freedom are dimers that occupy the edges between nearest neighbour vertices of a cubic lattice. Dimer occupancies are subject to the local constraint that every vertex is associated with exactly one dimer. In the presence of an aligning interaction, it is known that the system exhibits an unconventional continuous thermal phase transition from a symmetry broken columnar phase to a Coulomb-phase. The transition is in the NCCP1 universality class, which also describes the Neel-VBS transition in the JQ model and the S =1/2 Heisenberg model with suppression of hedgehog defects. Using Monte-Carlo simulations of a pair of defects in a background of fluctuating dimers, we calculate the scaling exponents for fugacities of monopole defects of charge Q = 2 and 3 at this critical point. Our estimates suggest that Q = 3 monopoles are relevant and could therefore drive the JQ model away from the NCCP1 critical point on a hexagonal lattice.

  11. SCC behavior of an Al-3. 7wt%Zn-2. 5wt%Mg alloys before and after welding in 3. 5% NaCl solution

    SciTech Connect

    Liao, C.M. )

    1993-01-01

    The behavior of stress corrosion cracking (SCC) of an overaged Al-3.7wt%Zn-2.5wt%Mg alloy including base metal, weldment, and heat-affected zone (HAZ) in 3.5% NaCl solution was investigated. This Al-Zn-Mg alloy loaded in longitudinal or long transverse direction has good SCC resistance and is maintained even after welding. Welding residual stress alone does not induce the SCC of the weldment. The result of the specially modified type 1 double cantilever beam (DCB) testing shows that the crack can be arrested by the weld metal because of the better SCC resistance of the filler metal ER5183. In addition, a specially designed type 2 DCB testing indicates that the SCC resistance of the HAZ is better than that of the base metal because of the re-overaging of the HAZ during welding.

  12. Expression of an alfalfa (Medicago sativa L.) peroxidase gene in transgenic Arabidopsis thaliana enhances resistance to NaCl and H2O2.

    PubMed

    Teng, K; Xiao, G Z; Guo, W E; Yuan, J B; Li, J; Chao, Y H; Han, L B

    2016-01-01

    Peroxidases (PODs) are enzymes that play important roles in catalyzing the reduction of H2O2 and the oxidation of various substrates. They function in many different and important biological processes, such as defense mechanisms, immune responses, and pathogeny. The POD genes have been cloned and identified in many plants, but their function in alfalfa (Medicago sativa L.) is not known, to date. Based on the POD gene sequence (GenBank accession No. L36157.1), we cloned the POD gene in alfalfa, which was named MsPOD. MsPOD expression increased with increasing H2O2. The gene was expressed in all of the tissues, including the roots, stems, leaves, and flowers, particularly in stems and leaves under light/dark conditions. A subcellular analysis showed that MsPOD was localized outside the cells. Transgenic Arabidopsis with MsPOD exhibited increased resistance to H2O2 and NaCl. Moreover, POD activity in the transgenic plants was significantly higher than that in wild-type Arabidopsis. These results show that MsPOD plays an important role in resistance to H2O2 and NaCl. PMID:27323080

  13. Ti{sub 5}O{sub 5} superstructures of cubic titanium monoxide

    SciTech Connect

    Gusev, A. I.

    2013-08-15

    A cubic model is proposed for the Ti{sub 5}O{sub 5} (Ti{sub 5} Black-Small-Square O{sub 5}{open_square} {identical_to} Ti{sub 90} Black-Small-Square {sub 18}O{sub 90}{open_square}{sub 18}) superstructure of nonstoichiometric titanium monoxide Ti{sub x}O{sub z} with double imperfection. The unit cell of the cubic Ti{sub 5}O{sub 5} superstructure has the threefold lattice parameter of the unit cell of the basis disordered B1 structure of Ti{sub x}O{sub z} monoxide and belongs to space group Pm 3-bar m . The channel of the disorder-order transition, i.e., Ti{sub x}O{sub z} (space group Fm 3-bar m)-Ti{sub 5}O{sub 5} (space group Pm 3-bar m), includes 75 superstructure vectors of seven stars (k{sub 10}), (k{sub 7}), (k{sub 6(1)}), (k{sub 6(2)}), (k{sub 4(1)}), (k{sub 4(2)}), and (k{sub 1}). The distribution functions of Ti and O atoms over the sites of the cubic Ti{sub 5}O{sub 5} superstructure are calculated. A comparison of the X-ray and electron diffraction data obtained for ordered TiO{sub 1.087} monoxide with the theoretical simulation results supports the existence of the cubic Ti{sub 5}O{sub 5} superstructure. The cubic (space group Pm 3-bar m) Ti{sub 5}O{sub 5} superstructure is shown to be a high-temperature structure relative to the well-known monoclinic (space group C2/m) superstructure of the same type.

  14. Transient concentrations of NaCl affect the PHA accumulation in mixed microbial culture.

    PubMed

    Palmeiro-Sánchez, T; Fra-Vázquez, A; Rey-Martínez, N; Campos, J L; Mosquera-Corral, A

    2016-04-01

    The present study explores the feasibility of the accumulation of polyhydroxyalkanoates (PHAs) under the presence of transient concentrations of added sodium chloride, by means of a mixed microbial culture (MMC). This culture was enriched on a mixture of volatile fatty acids (VFAs) containing 0.8g Na(+)/L as NaOH. This MMC presented a maximum PHA accumulation capacity of 53wt% with 27Cmol% HV. Accumulation experiments performed with added NaCl at concentrations of 7, 13 and 20g/L shown that this salt provoked a decrease of the biomass PHA production rate, with an IC50 value close to 7gNaCl/L. The accumulated PHA was lower than the corresponding value of the assay without the addition of salt. Furthermore, the composition of the biopolymer, in terms of HB:HV ratio, changed from 2.71 to 6.37Cmol/Cmol, which means a HV decrease between 27 and 14Cmol%. Summarizing, the PHA accumulation by a MMC non-adapted to saline conditions affected the polymer composition and lead to lower production yields and rates than in absence of added NaCl. PMID:26780589

  15. Evaporation of NaCl solution from porous media with mixed wettability

    NASA Astrophysics Data System (ADS)

    Bergstad, Mina; Shokri, Nima

    2016-05-01

    Evaporation of saline water from porous media is ubiquitous in many processes including soil salinization, crop production, and CO2 sequestration in deep saline acquirer. It is controlled by the transport properties of porous media, atmospheric conditions, and properties of the evaporating saline solution. In the present study, the effects of mixed wettability conditions on the general dynamics of water evaporation from porous media saturated with NaCl solution were investigated. To do so, we conducted a comprehensive series of evaporation experiments using sand mixtures containing different fractions of hydrophobic grains saturated with NaCl solutions. Our results showed that increasing fraction of hydrophobic grains in the mixed wettability sand pack had minor impact on the evaporative mass losses due to the presence of salt whose precipitation patterns were significantly influenced by the mixed wettability condition. Through macroscale and microscale investigations, we found formation of patchy efflorescence in the case of mixed wettability sand pack as opposed to crusty efflorescence in the case of completely hydrophilic porous media. Furthermore, the presence of salty water and hydrophobic grains in the sand pack significantly influenced the general dynamics and morphology of the receding drying front. Our results extend the understanding of the saline water evaporation from porous media with direct applications to various hydrological and engineering processes.

  16. Thermoluminescence analysis of co-doped NaCl at low temperature irradiations.

    PubMed

    Cruz-Zaragoza, E; Ortiz, A; Furetta, C; Flores, C; Hernández, J; Murrieta, H

    2011-02-01

    The thermoluminescent response and kinetics parameters of NaCl, doubly activated by Ca-Mn and Cd-Mn ions, exposed to gamma radiation are analyzed. The doped NaCl samples were irradiated at relative low temperature, i.e. at the liquid nitrogen temperature (LNT) and at dry ice temperature (DIT), and the glow curves obtained after 2 Gy of gamma irradiation were analyzed using the computerized glow curve deconvolution (CGCD). An evident variation in the glow curve structure after LNT and DIT was observed. It seems that different kinds of trapping levels are activated at relative low temperature. The original two prominent peaks in compositions A (Ca,Mn) and B (Ca,Mn) have been changed in only one main peak with satellites in the low temperature side of the glow curves. In compositions C (Cd,Mn) and D (Cd,Mn), low temperature peaks become stronger and prominent than the high temperature peaks; this effect could be explained considering that the trapping probability for low temperature traps, the one very close to the conduction band, is enhanced by low temperatures during irradiation. PMID:21093275

  17. Novel molecular variants of the Na-Cl cotransporter gene are responsible for Gitelman syndrome

    SciTech Connect

    Mastroianni, N.; De Fusco, M.; Casari, G.

    1996-11-01

    A hereditary defect of the distal tubule accounts for the clinical features of Gitelman syndrome (GS), an autosomal recessive disease characterized by hypokalemia, hypomagnesemia, metabolic alkalosis, and hypocalciuria. Recently, we cloned the cDNA coding for the human Na-Cl thiazide-sensitive cotransporter (TSC; also known as {open_quotes}NCCT{close_quotes} or {open_quotes}SLC12A3{close_quotes}) as a possible candidate for GS, and Simon et al., independently, described rotation in patients with GS. Now, we show 12 additional mutations consistent with a loss of function of the Na-Cl cotransporter in GS. Two missense replacements, R09W and P349L, are common to both studies and could represent ancient mutations. The other mutations include three deletions, two insertions, and six missense mutations. When all mutations from both studies are considered, missense mutations seem to be more frequently localized within the intracellular domains of the molecule, rather than in transmembrane or extracellular domains. One family, previously reported as a GS form with dominant inheritance, has proved to be recessive, with the affected child being a compound heterozygote. A highly informative intragenic tetranucleotide marker, useful for molecular diagnostic studies, has been identified at the acceptor splice site of exon 9. 12 refs., 3 figs., 2 tabs.

  18. Urotensin II and its receptor in the killifish gill: regulators of NaCl extrusion.

    PubMed

    Evans, David H; Hyndman, Kelly A; Cornwell, Emily; Buchanan, Patrick

    2011-12-01

    The peptide urotensin II (UII) and its receptor (UT) mediate cardiovascular and renal effects in both mammals and fishes. In both groups, vasopressor and diuretic responses predominate, although, in mammals, some secondary vasodilatation is found, mediated by secondary release of nitric oxide or prostacyclin. In fishes, gill extrusion of NaCl is inhibited by UII, but a single study has determined that UT is expressed in gill vasculature, not on the epithelium that mediates the transport. To begin to clarify the pathways involved in UII inhibition of gill transport, we have cloned the cDNA encoding UII and UT from the euryhaline killifish (Fundulus heteroclitus L.) gill and spinal cord, quantified UT mRNA expression in various tissues and measured relative expression in gill tissue from fish acclimated to seawater (SW) vs fresh water (FW). We have also localized UT in the gill epithelium, and measured the effect of UII on ion transport across the opercular epithelium. We found that both UII and UT are synthesized in the gill of F. heteroclitus and that gill UT mRNA levels are ~80% higher in SW- vs FW-acclimated individuals. In addition, UII inhibits NaCl transport across the opercular epithelium in a concentration-dependent manner, and this inhibition is at least partially mediated by both nitric oxide and a prostanoid. PMID:22071190

  19. [Effects of NaCl stress on photosynthesis characteristics and fast chlorophyll fluorescence induction dynamics of Pistacia chinensis leaves].

    PubMed

    Li, Xu-Xin; Liu, Bing-Xiang; Guo, Zhi-Tao; Chang, Yue-Xia; He, Lei; Chen, Fang; Lu, Bing-She

    2013-09-01

    By using fast chlorophyll fluorescence induction dynamics analysis technique (JIP-test), this paper studied the photosynthesis characteristics and fast chlorophyll fluorescence induction dynamics of 1-year old Pistacia chinensis seedlings under the stress of NaCl at the concentrations 0% (CK), 0.15%, 0.3%, 0.45%, and 0.6%. With the increasing concentration of NaCl, the contents of Chl a, Chl b, and Chl (a+b) in the seedlings leaves decreased, the Chl a/b ratio decreased after an initial increase, and the carotenoid content increased. The net photosynthetic rate (P(n)) and stomatal conductance (g(s)) decreased gradually with increasing NaCl concentration. The decrease of P(n) was mainly attributed to the stomatal limitation when the NaCl concentration was lower than 0.3%, and to the non-stomatal limitation when the NaCl concentration was higher than 0.3%. The trapped energy flux per RC (TR0/CS0), electron transport flux per RC (ET0/CS0), density of RCs (RC/CS0), and yield or flux ratio (psi(0) or phi(E0)) decreased, but the absorption flux per CS (ABS/CS0) and the K phase (W(k)) and J phase (V) in the O-J-I-P chlorophyll fluorescence induction curves increased distinctly, indicating that NaCl stress damaged the leaf oxygen-evolving complex (OEC), donor sides, and PS II reaction centers. When the NaCl concentration reached 0.3%, the maximum photochemical efficiency (F(v)/F(m)) and performance index (PI(ABS)) decreased 17.7% and 36.6%, respectively, as compared with the control. PMID:24417104

  20. Osmotic injury of PC-3 cells by hypertonic NaCl solutions at temperatures above 0 degrees C.

    PubMed

    Zawlodzka, Sylwia; Takamatsu, Hiroshi

    2005-02-01

    Cell injury due to osmotic dehydration, which is regarded as a major cause of injury during freeze-thaw processes, was examined closely using a perfusion microscope. Human prostatic adenocarcinoma cells (PC-3), which were put in a chamber, were subjected to hyperosmotic stresses by perfusing NaCl solutions of varying concentrations into the chamber. Cells were exposed to 2.5 and 4.5M NaCl solutions for 1-60 min by changing the concentrations at 0.2, 1, and 10 M/min. Decrease in cell viability was biphasic: the viability decreased first after the increase in NaCl concentration due to dehydration and then after return to isotonic conditions due to rehydration. Rehydration was substantially more responsible for cell injury than dehydration, which was marked at lower NaCl concentrations and lower temperatures. Injury resulting from contraction was negligible at the 2.5 M NaCl solution. While the hypertonic cell survival, which was determined without a return to isotonic conditions, was almost independent of time of exposure to hyperosmotic concentrations, the post-hypertonic survival after returning to isotonic conditions decreased with increasing exposure time, suggesting that the rehydration-induced injury was a consequence of time-dependent alteration of the plasma membrane. The post-hypertonic survival was lower for higher NaCl concentrations and higher temperatures, which was qualitatively consistent with previous studies. Effects of the rate of concentration change on the post-hypertonic cell survival were observed at 4.5 M; the highest rate of survival was obtained by slower increase and faster decrease in the NaCl concentration. However, the effect was negligible at 2.5 M. PMID:15710370

  1. A smoothing algorithm using cubic spline functions

    NASA Technical Reports Server (NTRS)

    Smith, R. E., Jr.; Price, J. M.; Howser, L. M.

    1974-01-01

    Two algorithms are presented for smoothing arbitrary sets of data. They are the explicit variable algorithm and the parametric variable algorithm. The former would be used where large gradients are not encountered because of the smaller amount of calculation required. The latter would be used if the data being smoothed were double valued or experienced large gradients. Both algorithms use a least-squares technique to obtain a cubic spline fit to the data. The advantage of the spline fit is that the first and second derivatives are continuous. This method is best used in an interactive graphics environment so that the junction values for the spline curve can be manipulated to improve the fit.

  2. Black holes in a cubic Galileon universe

    NASA Astrophysics Data System (ADS)

    Babichev, E.; Charmousis, C.; Lehébel, A.; Moskalets, T.

    2016-09-01

    We find and study the properties of black hole solutions for a subclass of Horndeski theory including the cubic Galileon term. The theory under study has shift symmetry but not reflection symmetry for the scalar field. The Galileon is assumed to have linear time dependence characterized by a velocity parameter. We give analytic 3-dimensional solutions that are akin to the BTZ solutions but with a non-trivial scalar field that modifies the effective cosmological constant. We then study the 4-dimensional asymptotically flat and de Sitter solutions. The latter present three different branches according to their effective cosmological constant. For two of these branches, we find families of black hole solutions, parametrized by the velocity of the scalar field. These spherically symmetric solutions, obtained numerically, are different from GR solutions close to the black hole event horizon, while they have the same de-Sitter asymptotic behavior. The velocity parameter represents black hole primary hair.

  3. Influence of NaCl content and cooling rate on outgrowth of Clostridium perfringens spores in cooked ham and beef.

    PubMed

    Zaika, Laura L

    2003-09-01

    The effect of NaCl concentration and cooling rate on the ability of Clostridium perfringens to grow from spore inocula was studied with the use of a process that simulates the industrial cooking and cooling of smoked boneless ham and beef roasts. NaCl was added to ground cooked hams A and B (which were commercially obtained) to obtain levels of 2.4, 3.1, 3.6, and 4.1% (wt/wt) and 2.8, 3.3, 3.8, and 4.3% (wt/wt), respectively, and to raw ground beef to obtain levels of 0, 1, 2, 3, and 4% (wt/wt). Ham C, a specially formulated, commercially prepared product, was supplemented with NaCl to obtain levels of 2.0, 2.5, 3.0, and 3.5%. The samples were inoculated with a three-strain mixture of C. perfringens spores to obtain concentrations of ca. 3 log10 CFU/g. Portions of meat (5 g each) were spread into thin layers (1 to 2 mm) in plastic bags, vacuum packaged, and stored at -40 degrees C. Thawed samples were heated at 75 degrees C for 20 min and subsequently cooled in a programmed water bath from 54.4 to < or = 8.5 degrees C in 15, 18, or 21 h. For the enumeration of C. perfringens, samples were plated on tryptose-sulfite-cycloserine agar and incubated in an anaerobic chamber at 37 degrees C for 48 h. Population densities for cooked ham and beef increased as cooling time increased, and NaCl exerted a strong inhibitory effect on the germination and outgrowth of C. perfringens. For beef, while 3% NaCl completely arrested growth, pathogen numbers increased by > or = 3, 5, and 5 log10 CFU/g in 15, 18, and 21 h, respectively, when the NaCl level was <2%. C. perfringens did not grow during cooling for 15, 18, or 21 h in ham samples containing > or = 3.1% NaCl. Results obtained in this study suggest that a 15-h cooling time for cooked ham, which is normally formulated to contain >2% NaCl, would yield an acceptable product (with an increase of <1 log10 CFU/g in the C. perfringens count); however, for beef containing <2% NaCl, C. perfringens populations may reach levels high

  4. Incorporation of Lactobacillus casei in Iranian ultrafiltered Feta cheese made by partial replacement of NaCl with KCl.

    PubMed

    Karimi, R; Mortazavian, A M; Karami, M

    2012-08-01

    Probiotic Iranian ultrafiltered Feta cheese was produced from ultrafiltration of milk with a volumetric concentration factor of 4.5:1. The heat-treated retentates were inoculated with 10(7) cfu of Lactobacillus casei LAFTI L26/mL. A mesophilic-thermophilic mixed culture of Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Streptococcus thermophilus was also used. Three percent (wt/wt) salt with different ratios of NaCl:KCl (100% NaCl, 50% NaCl:50% KCl, 75% NaCl:25% KCl, and 25% NaCl:75% KCl) were used in cheese formulation. The viability of L. casei was determined in treatments during the ripening period (90d at 5°C) within 15-d intervals. The pH, titratable acidity, and redox potential changes were monitored throughout the mentioned period. The mean pH drop rate, mean acidity increase rate, and mean redox potential increase rate were calculated at the end of the storage period. Also, total nitrogen, water-soluble nitrogen, lactic acid, and acetic acid concentrations, and syneresis and sensory characteristics of the product were measured during the mentioned period every 30d. The maximum viability of L. casei was observed within d 15 to 30 of the ripening period in the treatment containing the lowest amount of sodium. Addition of KCl enhanced syneresis. Cheeses with NaCl alone and with only 25% replacement by KCl have the highest sensory acceptability. PMID:22818434

  5. Consensus on the solubility of NaCl in water from computer simulations using the chemical potential route.

    PubMed

    Benavides, A L; Aragones, J L; Vega, C

    2016-03-28

    The solubility of NaCl in water is evaluated by using three force field models: Joung-Cheatham for NaCl dissolved in two different water models (SPC/E and TIP4P/2005) and Smith Dang NaCl model in SPC/E water. The methodology based on free-energy calculations [E. Sanz and C. Vega, J. Chem. Phys. 126, 014507 (2007)] and [J. L. Aragones et al., J. Chem. Phys. 136, 244508 (2012)] has been used, except, that all calculations for the NaCl in solution were obtained by using molecular dynamics simulations with the GROMACS package instead of homemade MC programs. We have explored new lower molalities and made longer runs to improve the accuracy of the calculations. Exploring the low molality region allowed us to obtain an analytical expression for the chemical potential of the ions in solution as a function of molality valid for a wider range of molalities, including the infinite dilute case. These new results are in better agreement with recent estimations of the solubility obtained with other methodologies. Besides, two empirical simple rules have been obtained to have a rough estimate of the solubility of a certain model, by analyzing the ionic pairs formation as a function of molality and/or by calculating the difference between the NaCl solid chemical potential and the standard chemical potential of the salt in solution. PMID:27036458

  6. Shape-memory NiTi foams produced by replication of NaCl space-holders.

    PubMed

    Bansiddhi, A; Dunand, D C

    2008-11-01

    NiTi foams were created with a structure (32-36% open pores 70-400 microm in size) and mechanical properties (4-25 GPa stiffness, >1000 MPa compressive strength, >42% compressive ductility, and shape-memory strains up to 4%) useful for bone implant applications. A mixture of NiTi and NaCl powders was hot-isostatically pressed at 950 and 1065 degrees C and the NaCl phase was then dissolved in water. The resulting NiTi foams show interconnected pores that replicate the shape and size of the NaCl powders, indicating that NiTi powders densified significantly before NaCl melted at 801 degrees C. Densifying NiTi or other metal powders above the melting point of the space-holder permits the use of NaCl, with the following advantages compared with higher-melting, solid space-holders such as oxides and fluorides used to date: (i) no temperature limit for densification; (ii) lower cost; (iii) greater flexibility in powder (and thus pore) shape; (iv) faster dissolution; (v) reduced metal corrosion during dissolution; (vi) lower toxicity if space-holder residues remain in the foam. PMID:18678532

  7. Molecular dynamics simulations of carbon dioxide hydrate growth in electrolyte solutions of NaCl and MgCl2

    NASA Astrophysics Data System (ADS)

    Yi, Lizhi; Liang, Deqing; Zhou, Xuebing; Li, Dongliang; Wang, Jianwei

    2014-12-01

    Molecular dynamics simulations are performed to study the growth of carbon dioxide (CO2) hydrate in electrolyte solutions of NaCl and MgCl2. The kinetic behaviour of the hydrate growth is examined in terms of cage content, density profile, and mobility of ions and water molecules, and how these properties are influenced by added NaCl and MgCl2. Our simulation results show that both NaCl and MgCl2 inhibit the CO2 hydrate growth. With a same mole concentration or ion density, MgCl2 exhibits stronger inhibition on the growth of CO2 hydrate than NaCl does. The growth rate of the CO2 hydrate in NaCl and MgCl2 solutions decreases slightly with increasing pressure. During the simulations, the Na+, Mg2+, and Cl- ions are mostly excluded by the growing interface front. We find that these ions decrease the mobility of their surrounding water molecules, and thus reduce the opportunity for these water molecules to form cage-like clusters toward hydrate formation. We also note that during the growth processes, several 51263 cages appear at the hydrate/solution interface, although they are finally transformed to tetrakaidecahedral (51262) cages. Structural defects consisting of one water molecule trapped in a cage with its hydrogen atoms being attracted by two Cl- ions have also been observed.

  8. Consensus on the solubility of NaCl in water from computer simulations using the chemical potential route

    NASA Astrophysics Data System (ADS)

    Benavides, A. L.; Aragones, J. L.; Vega, C.

    2016-03-01

    The solubility of NaCl in water is evaluated by using three force field models: Joung-Cheatham for NaCl dissolved in two different water models (SPC/E and TIP4P/2005) and Smith Dang NaCl model in SPC/E water. The methodology based on free-energy calculations [E. Sanz and C. Vega, J. Chem. Phys. 126, 014507 (2007)] and [J. L. Aragones et al., J. Chem. Phys. 136, 244508 (2012)] has been used, except, that all calculations for the NaCl in solution were obtained by using molecular dynamics simulations with the GROMACS package instead of homemade MC programs. We have explored new lower molalities and made longer runs to improve the accuracy of the calculations. Exploring the low molality region allowed us to obtain an analytical expression for the chemical potential of the ions in solution as a function of molality valid for a wider range of molalities, including the infinite dilute case. These new results are in better agreement with recent estimations of the solubility obtained with other methodologies. Besides, two empirical simple rules have been obtained to have a rough estimate of the solubility of a certain model, by analyzing the ionic pairs formation as a function of molality and/or by calculating the difference between the NaCl solid chemical potential and the standard chemical potential of the salt in solution.

  9. Effect of trace amounts of NaCl vapor on high-temperature oxidation of TiAl

    SciTech Connect

    Hara, M.; Kitagawa, Y.

    1999-08-01

    The effect of trace amounts of NaCl vapor on the high-temperature oxidation of TiAl was examined by thermogravimetry and analysis of the scale formed on TiAl. The mass gain due to oxidation at 1273 K in O{sub 2} with trace amounts of NaCl vapor was far lower than that in pure O{sub 2} without NaCl vapor. This low mass gain in the atmosphere with trace amounts of NaCl vapor resulted from the saturation behavior of mass gain during the initial period of oxidation. It was found from X-ray photoemission spectroscopy (XPS) analyses of the specimen surface that the oxide film formed during the initial period in the atmosphere with trace amounts of NaCl vapor consisted of dense Al{sub 2}O{sub 3}, thus, the low oxidation rate of TiAl was attributed to a protective oxide film of dense Al{sub 2}O{sub 3}.

  10. Photocatalytic water splitting for hydrogen generation on cubic, orthorhombic, and tetragonal KNbO3 microcubes

    NASA Astrophysics Data System (ADS)

    Zhang, Tingting; Zhao, Kun; Yu, Jiaguo; Jin, Jian; Qi, Yang; Li, Huiquan; Hou, Xinjuan; Liu, Gang

    2013-08-01

    Potassium niobate (KNbO3) microcubes with orthorhombic and tetragonal phases were hydrothermally prepared and characterized by powder X-ray diffraction, nitrogen adsorption-desorption, micro-Raman spectroscopy, Fourier transform infrared spectroscopy, diffuse reflectance UV-visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The photoreactivity of the as-prepared KNbO3 samples was evaluated regarding the hydrogen evolution from aqueous methanol under UV, and the results were compared with that of cubic KNbO3 microcubes. The photocatalytic reactivity was shown to be phase-dependent, following the order cubic > orthorhombic > tetragonal. Insight into the phase-dependent photocatalytic properties was gained by first-principles density functional calculations. The best photocatalytic performance of cubic KNbO3 is ascribed to it having the highest symmetry in the bulk structure and associated unique electronic structure. Further, the surface electronic structure plays a key role leading to the discrepancy in photoreactivity between orthorhombic and tetragonal KNbO3. The results from this study are potentially applicable to a range of perovskite-type mixed metal oxides useful in water splitting as well as other areas of heterogeneous photocatalysis.Potassium niobate (KNbO3) microcubes with orthorhombic and tetragonal phases were hydrothermally prepared and characterized by powder X-ray diffraction, nitrogen adsorption-desorption, micro-Raman spectroscopy, Fourier transform infrared spectroscopy, diffuse reflectance UV-visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The photoreactivity of the as-prepared KNbO3 samples was evaluated regarding the hydrogen evolution from aqueous methanol under UV, and the results were compared with that of cubic KNbO3 microcubes. The photocatalytic reactivity was